Zineb Ait Bahajji shared some pretty important information on Twitter this week for those who want rich snippets for their site – or who are struggling to get rich snippets to show up.

She said that Google doesn’t want to clutter up the search results too much but that another factor comes into play when it comes to which sites Google decides to show a rich snippet for (or not for).   Google will evaluate the other sites being shown in the same search query, then uses that data to decide which results have rich snippets.

She also said that length of time since the information for rich snippets was added to a page isn’t as much of a factor as quality and relevance are.

[Note: The translation shown by Twitter/Bing isn’t completely accurate, for those who translated via Twitter]

I have definitely seen this in action.  Sometimes sites will see rich snippets for some search results yet not others, and others wrongly assume that just because it appears for some pages that it will appear for all.  But this seems to imply it is not only directly about how high quality the specific page is, but also about how high quality the other 9 or so sites are that also appear on that page of search results.

But this also has some vital information for SEOs – if you want rich snippets to show for a particular query, you need to ensure that Google will consider your result one of the best, if not the best, on the page for that search result.  And while everyone should always want to increase the value of the site and individual pages, this gives SEOs a bit more to work with if they know they need to make sure those individual pages are of the highest quality if they see competitors with rich snippets while they don’t.

It also leans towards the fact Google is somehow evaluating rich snippet criteria slightly differently from the regular algorithm…. perhaps with higher emphasis on one specific aspect, such as content, after all the main search algo determines the page positions in the results.  After all, we do see some sites higher in the search results without rich snippets, while some lower in the results have them.

It also reflects on the fact that we definitely see some newly marked up pages begin to display rich snippets almost immediately while some never do.

The important takeaway is that you shouldn’t just be looking at your site and see a rich snippet and think everything is good.  Instead, evaluate your more important keywords and if they aren’t showing rich snippets, instead of assuming the problem is with Google (checking that your markup validates, of course), the problem could be with your own site in relation to those other 9 sites in the search results.