Rich Snippet's itemtype Product, Is it possible now to use it and apply it in a Classifieds Ads Website - rich-snippets

Question

I've just read about Google's Rich Snippet and I am planning to apply it on a Classifieds Ads Website.
Is it fine and effective if I use it in a Classifieds Ads Website?
I've asked this because, I've understood from my further readings that It only has effect on Products that can be purchased from the site where it is Posted and, that, that "Product" itemtype (itemtype="http://schema.org/Product") shall not be a PRODUCT LISTING, that can be purchase by contacting and paying the seller offline, or from off the website. In my classifieds ads website, the buyer contacts the seller if he wants to buy the item and they shall agree to meetup. Or when no meetups is possible, the seller sends the item to the buyer after the seller received the price amount from the buyer. And I got another inquiry, can we apply and use this snippet to a website similar to eBay?

Answer 1

The best way to model classified ads, with no explicit details of the products offered, for Google Rich Snippets is using the GoodRelations vocabulary, http://purl.org/goodrelations/ in RDFa syntax.
Simply use the gr:Offering class as shown below:
<div xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:gr="http://purl.org/goodrelations/v1#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
xml:lang="en" >
<!-- The Classified Ad content -->
<div about="#offering" typeof="gr:Offering">
<div rev="gr:offers" resource="#user1234"></div>
<strong property="gr:name" >Classified ad - headline (e.g. the text in bold)</strong>
<div property="gr:description">Here comes the full text of the classified ad ....
blablabla</div>
<!-- if you have an image, use this pattern -->
<img rel="foaf:depiction" src="http://www.heppnetz.de/rdfa4google/image.jpg" />
<!-- if you know the type of business function (Sell, LeaseOut, Dispose, ProvideService,
attach it like this -->
<div rel="gr:hasBusinessFunction"
resource="http://purl.org/goodrelations/v1#Sell"></div>
<!-- if you can provide the price in a structured form, use this pattern
(needed for Rich Snippets) -->
<div rel="gr:hasPriceSpecification">
<div typeof="gr:UnitPriceSpecification">
<div property="gr:hasCurrency" content="USD" datatype="xsd:string"></div>
<div property="gr:hasCurrencyValue" content="89" datatype="xsd:float"></div>
</div>
</div>
<!-- provide the URI of a deep link to the page -->
<div rel="foaf:page" resource="http://www.heppnetz.de/rdfa4google/tc16.html"></div>
</div>
This validates in the Google Rich Snippets Testing Tool, as you can see here.
For your convenience, I just created a respective recipe in the GoodRelations Cookbook:
http://wiki.goodrelations-vocabulary.org/Cookbook/Classifieds
Hope that helps!