Google Rich Snippets displayed only in some language versions of Google search?

There are multiple reasons for this:

1. Google is rolling out rich snippets for products gradually, i.e., it is not yet globally deployed. I have seen rich snippets for products working on google.com, google.de, and google.co.uk. I have not yet seen them on the smaller localizations, like google.pt, google.pl, and google.fr.

2. To my knowledge, there is a mechanism in place that assesses whether rich snippets for a given page should be displayed, i.e., it is not guaranteed that rich snippets will be displayed for a given page. Google tries to assess the trustworthiness and quality of the markup and the site in general.

I suspect that the second mechanism takes into account a multitude of signals from the site and from the query, so it may be that the same page shows rich snippets in one country but not in another country, even if that country has, in general, already rich snippets support.

Despite this uncertainty, it makes sense to add rich markup for products to your site rather now than later, because:

1. Once rich snippets are turned on for your country, your products will show rich snippets before your competitors' pages will, because the Google cache will already contain your rich markup, while people starting to markup their pages once the support is there will have to wait for 4 - 10 weeks for a full recrawl.

2. Content that has been existent for a while seems to get a bonus in the various Google scoring systems, so having rich markup in your pages for a sustained amount of time may increase the likelihood of seeing rich snippets for your page.

A recipe for adding GoodRelations in RDFa to your page is here:

http://wiki.goodrelations-vocabulary.org/Quickstart

A tool for generating markup snippets is here:

http://www.ebusiness-unibw.org/tools/grsnippetgen/

Best Martin Hepp