I have a client which is shipping via UPS, and therefore cannot deliver to Post Office boxes. I would like to be able to validate customer address fields in order to prevent them from entering addresses which include a PO box. It would be best if this were implemented as a regex so that I could use a client-side regex validation control (ASP.NET).
I realize there's probably no way to get a 100% detection rate, I'm just looking for something that will work most of the time.
UPS also has tools that you can integrate to do this... that way you can verify an address exactly as to whether or not they will ship, what the cost would be, schedules, etc. I suggest visiting the UPS IT Solutions page for more information.
This should get you started. Test to see if the Address field matches this regex.
"^P\.?\s?O\.?\sB[Oo][Xx]."
Translation to English: That's a P at the beginning of the line, followed by an optional period and space, followed by an O, followed by an optional period, followed by a space, followed by "Box", followed by anything else.
You might be better off putting a disclaimer on the page warning that you can not ship to post office boxes, opposed to validating the input.
More than likely if you do create a regex that catches most of the P.O. Box scenarios, there's a good chance it'll also catch things you weren't intending (i.e. a customer with a street name containing the letters 'p' 'o' and 'box')
Unfortunately, UPS's online software allows P.O. Boxes to go through, but will choke on them once they're in the shipping channel.
In our case, our cart abandonment rate went up when we tried to gracefully prevent P.O. Boxes. We found it much more cost effective to leave it alone, accept the sale, bring it to the attention of customer service, and let them resolve it.
Of course, if you get a high incidence of P.O Boxes, this may not be the case for you.
I'd start with a regex ala Lizard (but use the "ignore case" flag :)), test on historical data, then iterate as you see what invalid inclusions and exclusions you see in testing.
Most shipping providers (for example FedEx) will validate the shipping address. For example, with FedEx web services, there is a call to validate a shipping address and get the estimated cost. This not only ensures that the address is not a PO Box, but also makes sure that the rest of the address is valid.
Regarding the OP's comment to Jason Coco's answer:
Since you're in a position to add regex validation to the shipping address, I assume that you have control of the application (i.e., you have the source and can modify it). If that's the case, then you should have the ability to, on reciept of the submitted data, check whether it is to be shipped via USPS, FedEx, or UPS and submit a request to the appropriate shipper-specific address validator, gaining all the benefits suggested in Jason's answer.
By making it shipper-specific, this would also allow you to avoid implementing one-size-fits-all rules, such as "no PO boxes because UPS doesn't deliver to them", even though the user can select non-UPS shippers who do deliver to PO boxes.
What if it doesn't start with "PO Box.." or "P.O. Box" ?
Example:
John Schmidt |
Silver Valley PO Box 3901 |
Whereswaldoville, SI. 78946
I used an onblur event for the address field to use a javascript function, indexOf, to recognize the input.toUpperCase "PO BOX" || "P.O" that is >= 0.
If either of these two searches are not found, the return is -1, otherwise, it will return the string's start position which will always be 0 or more.
This will ensure that lazy typing, 'po box,' 'p.o box,' and as well as 'p.o. box' will be recognized. I suppose you could add 'po. box' as well.
Anyway, the condition triggers an unobtrusive message to show that 'We can't ship to a PO Box address." It's a feature to not see it if it doesn't apply to you. Otherwise, for users who don't have js or css enabled, they'll just see the message. The only fail on this graceful degradation is if a user has css, but not js enabled (where they just won't see the message at all). I only came up with the solution today, but if I think of a better way, I'll come back to post it here.
Related
First of all, sorry for the long text. Second, I decided to ask this on Stack Overflow rather than somewhere like Law Stack Exchange because the reason for the question is GDPR but the question itself is about software architecture.
I've been trying to pay attention regarding what one must do concerning GDPR and everything I find always seems to assume that one is working with user accounts, i.e. that users register on your website and that everything or almost everything you need to care about GDPR in terms of safeguarding your users' data starts here. It is also my understanding that one must be able to prove that their users gave their consent to you using their data as per in a privacy policy and even to which version of the privacy policy they consented to (since these sometimes get updated). This necessarily means that the data regarding this proof of consent must be stored server-side. This is easy to do when you have a user account to bind this data to but what about when you work with non-registered or guest users?
Let me give you a little background for my actual question: as a personal project I'm currently building a small website which will allow users to add comments to certain pages and even submit photos. The thing is, this is the only interaction users can do at all, so I don't want nor need them to have an account, making it also one less thing to worry about and allowing for easier engagement with the site. For the comments the only thing that's really needed is the comment text itself and some user name (which can be anything from their real name to some alias, it doesn't really matter). I'll also add an optional field for the user to state where they're from -- say, "Paris, France" -- if they so wish to share that.
Anyway, all of this just begs for spam to come my way, so I was thinking of integrating Akismet and Google's reCAPTCHA, since that has worked very well for me in the past. The problem is that Akismet requires an email address to also be passed on to it in order for it to check if the comment is spam, so I would also need to ask users for their email address on the comments form. Since I literally only need their email while checking for spam and would never make it public anyway, I would save it in the database and get rid of it after a few days or so and communicate this on the site's privacy policy.
So, here comes the question. I think email addresses together with the other info above count as PII and since I'm storing email address and sharing them with a third party, it seems clear to me that I have to ask users for their consent to do so, and not allow for their comment to be submitted if they don't give their consent, of course. But there are no actual user accounts in place here so there's no central location for such consent to be stored as proof. So how does one go about this? The only thing I can think of is having a checkbox on the comment form and storing its value together with the comment. Of course, with proper validation in place the stored value will always be 1, but still, it needs to be explicitly stored for it to be GDPR-compliant. I don't love the idea of a user having to check a checkbox agreeing with the privacy policy everytime they want to comment on something, but I don't think I see another way around this. Do you?
Many thanks in advance and, again, sorry for the long text.
My boss wants me to fashion a QR code so that when the user scans it, it displays a button that when clicked:
(1) Will take the user to our website.
(2) Will quietly send us a text message.
The purpose of #2 is to allow us to gather their phone number.
In addition to being a privacy violation, I'm pretty sure this (and any other means of achieving this), is technically impossible. Is that correct?
My understanding of QR codes is that they only contain text. That text may contain keywords which a good reader may parse and display buttons for. It seems the closest I can get to my employer's requirement is to use an SMSTO: link in the QR code, so that (given an appropriate reader) the user is prompted to send us an SMS, at which point we can get their number.
Can anyone think of another way of doing this?
(any other clarification also welcome)
It is technically impossible.
As you say, the best you can do is create an smsto: link.
What you can do is create a code with the instruction
"Scan the code to receive our website by SMS"
Then, create a code with
smsto:123456:website
This will send the keyword "website" to a phone number. You'll need to set up a phone number which can auto-respond with the URL you want. There are commercial services which do this (depending on where you are in the world). Or look at a service like FrontlineSMS which can send the texts on your behalf.
Important: This question isn't actually really an ASP.NET question. Anyone who knows anything about URLS can answer it. I just happen to be using ASP.NET routing so included that detail.
In a nutshell my question is :
"What URL format should I design that i can give to external parties to get to a specific place on my site that will be future proof. [I'm new to creating these 'REST' URLs]."
I need an ASP.NET routing URL that will be given to a third party for tracking marketing campaigns. It is essentially a 'gateway' URL that redirects the user to a specific page on our site which may be the homepage, a special contest or a particular product.
In addition to trying to capture the referrer I will need to receive a partnerId, a campaign number and possibly other parameters. I want to provide a route to do this BUT I want to get it right first time because obviously I cant easily change it once its being used externally.
How does something like this look?
routes.MapRoute(
"3rd-party-campaign-route",
"campaign/{destination}/{partnerid}/{campaignid}/{custom}",
new
{
controller = "Campaign",
action = "Redirect",
custom = (string)null // optional so we need to set it null
}
);
campaign : possibly don't want the word 'campaign' in the actual link -- since users will see it in the URL bar. i might change this to just something cryptic like 'c'.
destination : dictates which page on our site the link will take the user to. For instance PR to direct the user to products page.
partnerid : the ID for the company that we've assigned - such as SO for Stack overflow.
campaignid : campaign id such as 123 - unique to each partner. I have realized that I think I'd prefer for the 3rd party company to be able to manage the campaign ids themselves rather than us providing a website to 'create a campaign'. I'm not
completely sure about this yet though.
custom : custom data (optional). i can add further custom data parameters without breaking existing URLS
Note: the reason i have 'destination' is because the campaign ID is decided upon by the client so they need to also tell us where the destination of that campaign is. Alternatively they could 'register' a campaign with us. This may be a better solution to avoid people putting in random campaign IDs but I'm not overly concerned about that and i think this system gives more flexibility.
In addition we want to know perhaps which image they used to link to us (so we can track which banner works the best). I THINK this is a candiate for a new campaignid as opposed to a custom data field but i'm not sure.
Currently I am using a very primitive URL such as http://example.com?cid=123. In this case the campaign ID needs to be issued to the third party and it just isn't a very flexible system. I want to move immediately to a new system for new clients.
Any thoughts on future proofing this system? What may I have missed? I know i can always add new formats but I want to use this format as much as possible if that is a good idea.
This URL:
"campaign/{destination}/{partnerid}/{campaignid}/{custom}",
...doesn't look like a resource to me, it looks like a remote method call. There is a lot of business logic here which is likely to change in the future. Also, it's complicated. My gut instinct when designing URLs is that simpler is generally better. This goes double when you are handing the URL to an external partner.
Uniform Resource Locators are supposed to specify, well, resources. The destination is certainly a resource (but more on this in a moment), and I think you could consider the campaign a resource. The partner is not a resource you serve. Custom is certainly not a resource, as it's entirely undefined.
I hear what you're saying about not wanting to have to tell the partners to "create a campaign," but consider that you're likely to eventually have to go down this road anyway. As soon as the campaign has any properties other than the partner identifier, you pretty much have to do this.
So my first to conclusions are that you should probably get rid of the partner ID, and derive it from the campaign. Get rid of custom, too, and use query string parameters instead, should it be necessary. It is appropriate to use query string parameters to specify how to return a resource (as opposed to the identity of the resource).
Removing those yields:
"campaign/{destination}/{campaignid}",
OK, that's simpler, but it still doesn't look right. What's destination doing in between campaign and campaign ID? One approach would be to rearrange things:
"campaign/{campaignid}/{destination}",
Another would be to use Astoria-style indexing:
"campaign({campaignid})/{destination}",
For some reason, this looks odd to a lot of people, but it's entirely legal. Feel free to use other legal characters to separate campaign from the ID; the point here is that a / is not the only choice, and may not be the appropriate choice.
However...
One question we haven't covered yet is what should happen if/when the user submits a valid destination, but an invalid campaign or partner ID. If the correct response is that the user should see an error, then all of the above is still valid. If, on the other hand, the correct response is that the user should be silently taken to the destination page anyway, then the campaign ID is really a query string parameter, not a part of the resource. Perhaps some partners wouldn't like being given a URL with a question mark in it, but from a purely REST point of view, I think that's the right approach, if the campaign ID's validity does not determine where the user ends up. In this case, the URL would be:
"campaign/{destination}",
...and you would add a query string parameter with the campaign ID.
I realize that I haven't given you a definite answer to your question. The trouble is that most of this rests on business considerations which you are probably aware of, but I'm certainly not. So I'm more trying to cover the philosophy of a REST-ful URL, rather than attempting to explain your business to you. :)
I think the URL rewriting is getting out of hand a little bit lately. Not everything belongs to the URL. After all, a URL is supposed to describe a resource that can be searched for, discovered or manipulated and it seems to me that at least the partner ID and the custom fields from above are not part of the resource.
Not to mention that that at some point you would like to actually keep the partner ID constant across multiple campaigns and that means that it is now orthogonal to the particular places they need to visit. If you keep these as parameters, you will allow your partners to access uniformly multiple resources on your website, while still reliably identifying themselves, so you can track their participation in any of your campaigns.
It looks like you've covered all of your bases. The only suggestion I have is to change
{custom}
to
{*custom}
That way, if you ever need to accept further parameters, you don't have to take the chance that old URLs will get a 404. For example:
If you have a URL that looks like:
campaign/PR/SO/123
and you decide in the future that you would like to accept a fourth and fifth parameter:
campaign/PR/SO/123/blah/foo
then the first URL will still be valid, because you're using a wildcard character in {*custom}. "blah/foo" would be passed as a string to your action. To get those extra two parameters, you would simply split the custom argument in your action by '/'. Add some friendly error handling if they don't exist and you've successfully changed the amount of information you can receive with a campaign URL without completely breaking URLs already in the wild.
Why not use URL encoded variables instead of routes? They're a lot more flexible - you can add any new features in the future while still maintaining 100% backwards compatibility. Admittedly, it's a little more trouble to type manually, but if there's all those parameters anyway, it's already no picnic.
http://mysite.com/page?campaign=1&dest=products&pid=15&cid=25
To me, this is much more indicative of what is really going on. Using paths implies a that a resource exists at that location. But really you're just providing a web service with various parameters, and this model captures that much more clearly. And in the future, you can add more parameters effortlessly. You can also default parameters if they are missing without messing anything up.
Not sure of the code in ASP, but it should be trivial to implement.
I think I'd look at doing it the way that SO does it's questions.
"campaign/{campaign-id}/friendly-name-of-campaign"
Create a mapping in your database when the campaign is created that associates all the data you need with an automatically generated id. The friendly name could be assigned basically the same way as a question is on SO -- by the user -- but you could also have an approval process that makes sure that it meets your requirements and is distinct from any existing campaign names. Your tracking company can track by the id and you can correlate that with your associated data with a simple look up.
What you have looks good for your needs. The other posts here have good points. But may not be suitable for you. One thing that you could consider with future proofing your links is to put a version number somewhere in there.
"campaign/{version}/{destination}/{partnerid}/{campaignid}/{custom}"
This way if you decide to completely change your format you can up the version to 2.0 (or whatever) and still keep track of the old links coming in.
I would do
/c/{destination}/{partnerid}/{campaignid}/?customvar=s
You should think about the hierarchy of the first parameters, you already got that managed quite well. Only if there's a hierarchy path segments should be used.
From your description, destination seems to be the broadest parameter, partnerid only works with destination, and campaingid is specific to a partner.
When you really need to add custom parameters I would go for query variables (they are not forbidden in REST), because these are not part of the hierarchy.
You also shouldn't try to be too RESTful here. After all, it's for a campaign and for redirecting to a final resource. So the URL you want to design here is not really a specific resource in the terms of REST.
Create an URL called http://mysite.com/gateway
Return an HTML form, tell your partners to fill in the form and POST it. Redirect based on the form values.
You could easily provide your partners with the javascript to do the GET and POST. Should be trivial.
The most important thing i have learned about REST URL´s thats usually burried deep in some book or article:
The URL should point to a resource and the following ?querystring should have all the scoping information needed. DONT mix those two or you will have a design thats very hard to work with.
Other then that i fully agree with Craig Stuntz
Now, I realise the initial response to this is likely to be "you can't" or "use analytics", but I'll continue in the hope that someone has more insight than that.
Google adwords with "autotagging" appends a "gclid" (presumably "google click id") to link that sends you to the advertised site. It appears in the web log since it's a query parameter, and it's used by analytics to tie that visit to the ad/campaign.
What I would like to do is to extract any useful information from the gclid in order to do our own analysis on our traffic. The reasons for this are:
Stats are imperfect, but if we are collating them, we know exactly what assumptions we have made, and how they were calculated.
We can tie the data to the rest of our data and produce far more accurate stats wrt conversion rate.
We don't have to rely on javascript for conversions.
Now it is clear that the gclid is base64 encoded (or some close variant), and some parts of it vary more than others. Beyond that, I haven't been able to determine what any of it relates to.
Does anybody have any insight into how I might approach decoding this, or has anybody already related gclids back to compaigns or even accounts?
I have spoken to a couple of people at google, and despite their "don't be evil" motto, they were completely unwilling to discuss the possibility of divulging this information, even under an NDA. It seems they like the monopoly they have over our web stats.
By far the easiest solution is to manually tag your links with Google Analytics campaign tracking parameters (utm_source, utm_campaign, utm_medium, etc.) and then pull out that data.
The gclid is dependent on more than just the adwords account/campaign/etc. If you click on the same adwords ad twice, it could give you different gclids, because there's all sorts of session and cost data associated with that particular click as well.
Gclid is probably not 100% random, true, but I'd be very surprised and concerned if it were possible to extract all your Adwords data from that number. That would be a HUGE security flaw (i.e. an arbitrary user could view your Adwords data). More likely, a pseudo-random gclid is generated with every impression, and if that ad is clicked on, the gclid is logged in Adwords (otherwise it's thrown out). Analytics then uses that number to reconcile the data with Adwords after the fact. Other than that, there's no intrinsic value in the gclid number itself.
In regards to your last point, attempting to crack or reverse-engineer this information is explicitly forbidden in both the Google Analytics and Google Adwords Terms of Service, and is grounds for a permanent ban. Additionally, the TOS that you agreed to when signing up for these services says that it is not your data to use in any way you feel like. Google is providing a free service, so there are strings attached. If you don't like not having complete control over your data, then there are plenty of other solutions out there. However, you will pay a premium for that kind of control.
Google makes nearly all their money from selling ads. Adwords is their biggest money-making product. They're not going to give you confidential information about how it works. They don't know who you are, or what you're going to do with that information. It doesn't matter if you sign an NDA and they have legal recourse to sue you; if you give away that information to a competitor, your life isn't worth enough to pay back the money you will have lost them.
Sorry to break it to you, but "Don't be Evil" or not, Google is a business, not a charity. They didn't become one of the most successful companies in the world by giving away their search algorithm to the first guy who asked for it.
The gclid parameter is encoded in Protocol Buffers, and then in a variant of Base64.
See this guide to decoding the gclid and interpreting it, including an (Apache-licensed) PHP function you can use.
There are basically 3 parameters encoded inside it, one of which is a timestamp. The other 2 as yet are not known.
As far as understanding what these other parameters mean—it may be helpful to compare it to the ei parameter, which is encoded in an extremely similar way (basically Protocol Buffers with the keys stripped out). The ei parameter also has a timestamp, with what seem to be microseconds, and 2 other integers.
FYI, I just posted a quick analysis of some glcid data from my sites on this post. There definitely is some structure to the gclid, but it is difficult to decipher.
I think you can get all the goodies linked to the gclid via google's adword api. Specifically, you can query the click performance report.
https://developers.google.com/adwords/api/docs/appendix/reports#click
I've been working on this problem at our company as well. We'd like to be able to get a better sense of what our AdWords are doing but we're frustrated with limitations in Analytics.
Our current solution is to look in the Apache access logs for GET requests using the regex:
.*[?&]gclid=([^$&]*)
If that exists, then we look at the referer string to get the keyword:
.*[?&]q=([^$&]*).*
An alternative option is to change your Apache web log to start logging the __utmz cookie that google sets, which should have a piece for the keyword in utmctr. Google __utmz cookie and you should be able to find plenty of information.
How accurate is the referer string? Not 100%. Firewalls and security appliances will strip it out. But parsing it out yourself does give you more flexibility than Google Analytics. It would be a great feature to send the gclid to AdWords and get data back, but that feature does not look like it's available.
EDIT: Since I wrote this we've also created our own tags that are appended to each destination url as a request parameter. Each tag is just an md5 hash of the text, ad group, and campaign name. We grab it using regex from the access log and look it up in a SQL database.
This is a non-programmatic way to decode the GCLID parameter. Chances are you are simply trying to figure out the campaign, ad group, keyword, placement, ad that drove the click and conversion. To do this, you can upload the GCLID into AdWords as a separate conversion type and then segment by conversion type to drill down to the criteria that triggered the conversion. These steps:
In AdWords UI, go to Tools->Conversions->Add conversion with source "Import from clicks"
Visit the AdWords help topic about importing conversions https://support.google.com/adwords/answer/7014069 and create a bulk load file with your GCLID values, assigning the conversions to you new "Import from clicks" conversion type
Upload the conversions into AdWords in Tools->Conversions->Conversion actions (Uploads) on left navigation
Go to campaigns tab, Segment->Conversions->Conversion name
Find your new conversion name in the segment list, this is where the conversion came from. Continue this same process on the ad groups and keywords tab until you know the GCLID originating criteria
Well, this is no answer, but the approach is similar to how you'd tackle any cryptography problem.
Possibility 1: They're just random, in which case, you're screwed. This is analogous to a one-time pad.
Possibility 2: They "mean" something. In that case, you have to control the environment.
Get a good database of them. Find gclids for your site, and others. Record all times that all clicks occur, and any other potentially useful data
Get cracking! As you have started already, start regressing your collected data against your known, and see if you can find patterns used decrypting techniques
Start scraping random gclid's, and see where they take you.
I wouldn't hold high hope for this to be successful though, but I do wish you luck!
Looks like my rep is weak, so I'll just post another answer rather than a comment.
This is not an answer, clearly. Just voicing some thoughts.
When you enable auto tagging in Adwords, the gclid params are not added to the destination URLs. Rather they are appended to the destination URLs at run time by the Google click tracking servers. So, one of two things is happening:
The click servers are storing the gclid along with Adwords entity identifiers so that Analytics can later look them up.
The gclid has the entity identifiers encoded in some way so that Analytics can decode them.
From a performance perspective it seems unlikely that Google would implement anything like option 1. Forcing Analytics to "join" the gclid to Adwords IDs seems exceptionally inefficient at scale.
A different approach is to simply look at the referrer data which will at least provide the keyword which was searched.
Here's a thought: Is there a chance the gclid is simply a crytographic hash, a la bit.ly or some other URL shortener?
In which case the contents of the hashed text would be written to a database, and replaced with a unique id.
Afterall, the gclid is shortening a bunch of otherwise long text.
Takes this example:
www.example.com?utm_source=google&utm_medium=cpc
Is converted to this:
www.example.com?gclid=XDF
just like a URL shortener.
One would need a substitution cipher in order to reverse engineer the cryptographic hash... not as easy task: https://crypto.stackexchange.com/questions/300/reverse-engineering-a-hash
Maybe some deep digging into logs, looking for patterns, etc...
I agree with Ophir and Chris. My feeling is that it is purely a serial number / unique click ID, which only opens up its secrets when the Analytics and Adwords systems talk to each other behind the scenes.
Knowing this, I'd recommend looking at the referring URL and pulling as much as possible from this to use in your back end click tracking setup.
For example, I live in NZ, and am using Firefox. This is a search from the Firefox Google toolbar for "stack overflow":
http://www.google.co.nz/search?q=stack+overflow&ie=utf-8&oe=utf-8&aq=t&client=firefox-a&rlz=1R1GGLL_en-GB
You can see that: a) im using .NZ domain, b) my keyword "stack+overflow", c) im running firefox.
Finally, if you also stash the full landing page URL, you can store the GCLID, which will tell you the visitor came from paid, whereas if it doesn't have a GCLID, then the user must have come from natural search (if URL tagging is enabled of course).
This would theoretically allow you to then search for the keyword in your campaign, and figure out which adgroup them came from. Knowing the creative would probably be impossible though, unless you split test your landing URLs or tag them somehow.
I'm working on a web-based contest which is supposed to allow anonymous users to vote, but we want to prevent them from voting more than once. IP based limits can be bypassed with anonymous proxies, users can clear cookies, etc. It's possible to use a Silverlight application, which would have access to isolated storage, but users can still clear that.
I don't think it's possible to do this without some joker voting himself up with a bot or something. Got an idea?
The short answer is: no. The longer answer is: but you can make it arbitrarily difficult. What I would do:
Voting requires solving a captcha (to avoid as much as possible automated voting). To be even more effective I would recommend to have prepared multiple types of simple captchas (like "pick the photo with the cat", "what is 2+2", "type in the word", etc) and rotate them both by the time of the day and by IP, which should make automatic systems ineffective (ie if somebody using IP A creates a bot to solve the captcha, this will become useless the next day or if s/he distributes it onto other computers/uses proxies)
When filtering by IP you should be careful to consider situations where multiple hosts are behind one public IP (AFAIK AOL proxies all of their customers through a few IPs - so such a limitation would effectively ban AOL users). Also, many proxies send along headers pointing to the original IP (like X-Forwarded-For), so you can take a look at that too.
Finally, using something like FSO (Flash Shared Objects - "Flash cookies") is obscure enough for 99.99% of the people not to know about. Silverlight is even more obscure. To be even sneakier, you could buy an other domain and set the FSO from that domain (so, if the user is looking for FSO's set by your domain, they won't see any)
None of these methods is 100%, but hopefully combined they give you the level of assurance you need. If you want to take this a level higher, you need to add some kind of user registration (which can be as simple as asking a valid e-mail address when the vote occurs and sending a confirmation link to the given address and not counting the votes for which the link wasn't clicked - so it doesn't need to be a full-fledged "create an account with username / password / firs name / last name / etc").
No, you can't, and it only takes one person and a willing forum to change the outcome of an online vote.
You have to realize the inherent flaws of an online vote and rather than attempting to get around them try to use them to your advantage.
-Adam
You can certainly make it difficult.
What about building a user profile with such things as ip address, browser useragent, machine name, and whatever other information you can get.
Store the profile for each user, then if you receive a profile which is similar enough to one already in the database (you'll have to tweak that) you can throw out that vote.
I imagine you can probably build a better profile using silverlight, though I'm not sure what information that gives you access to.
Client-side solutions are out for the reasons you listed -- they can be manipulated by the user. Server-side solutions -- as you said -- can be fooled and bypassed.
If you're willing to accept the fact that you can't really be 100% sure that you're getting exactly one vote per person, then there are some measures you can take to reduce the noise.
Use a CAPTCHA in your vote-submission form to make it harder for bots and scripts to vote.
Limit the number of votes per IP address to one.
Consider requiring registration in order to vote. (I know this defeats part of your original question, but it gives you a greater degree of control over the voting.)
That's a good start.
my personal experience in contest developing and monitoring tells me that no, there is no reliable way to avoid cheating if you let anonymous users vote (or do anything that lets them participate in the contest).
you could play with IP, introduce delays between an action and the next, but it's really difficult: the best way is introduce a captcha or something similar, if applicable in your particular situation.
best of all, don't let anonymous users participate: let them "play" and access to a simulation, but the contest needs a login.
Nope, it's the user's computer and they're in control.
Unfortunately the only solution is to bring it back on your court so to speak and require authentication.
However, a CAPTCHA helps limit the votes to human users at least.
Of course even with authentication you can't enforce single voting because then they teach the bots to register...
I have to agree that the short answer is no...though if you look at my recent answer here: How to anonymously identify a user and store that information you certainly can get it within a 6 percent margin of error.