The technique used by search engines is not as simple as "rich snippets on" vs. "rich snippets off".
All major engines have to use software components that assess the quality (e.g. is the price current?) and trustworthiness (e.g. is the data in line with the page content and is the page a relevant resource?) of the meta-data. They will only show a rich snippet / rich caption if a page passes this test.
Quite likely, but I have to speculate in here, such a component uses multiple signals from the page to decide upon whether to show a rich snippet / rich caption or not, same as the normal relevance ranking can consider more than 100 - 200 signals from a page (including speed, domain age, ...). So the general importance and ranking of your site domain may e.g. influence whether you see a rich snippet, but that is again not the whole storey:
At least the following four things must be in place for seeing a rich snippet / caption in a search engine:
1. There must be valid rich markup in the page (or the search engine has access to the data from a bilateral data exchange, as it happens with a few top sites).
2. The markup must have been there when the page was last crawled / indexed, i.e., the meta-data must be in the caches.
3. Rich Snippets must be turned on for the local version of the search engine you are using (note that search engines may run multiple versions of their user interface even in the same country, for testing or for deployment reasons.)
4. The software component indicated above must think that showing a rich snippet for your page is likely a good thing.
If you do not see a rich snippet, this can have a wealth of causes:
1. The meta-data markup is invalid or incomplete. (Solution: fix the markup)
2. The meta-data is not yet in the search engine's index. (Solution: 1. wait 2. implement sitemap.xml properly, especially with correct lastmod attributes.)
3. Rich Snippets are not yet available in the local version of the search engine (Solution: Wait and hope and pray)
4. The search engine is not convinced that your meta-data adds valuable information to Web users (Solution: 1. Re-use visible content for markup 2. Make sure your page is up to 2011 SEO standards in general, i.e. has a good basic ranking, fast page loading times, "clean" item page URIs, relevant, real external links, relevant keywords, ... - basic SEO stuff)
Note that the assessment mechanism and/or its calibration may be different for different countries, so while your page may pass the test for the US version of a search engine, it may not pass the test for the Italian version.
I also assume that the calibration of the "gatekeeper" component #4 will depend on the number of available training data, so the search engines can allow more rich snippets for a country / language / region / local version for which they already have a lot of pages with meta-data markup. So if you are among the first sites to use rich mark-up in your country, you may have to wait a little bit longer than in a country where rich mark-up is already widely used.
So from not seeing a Rich Snippet despite rich markup, you cannot easily derive that there are no rich snippets turned on for your country.
Hope that helps!
On Sep 27, 2011, at 4:35 PM, Roy Lachica wrote:
e-business & web science research group
universitaet der bundeswehr muenchen
www: http://www.unibw.de/ebusiness/ (group)