It's a good suggestion. The fact is, we're going to take it slowly at first, to sort of make sure that people are doing good things with Rich Snippets. For example, you could imagine going crazy with Rich Snippets and it might actually cause the click-through to go down, if users didn't like those sort of Rich Snippets.
So we've been relatively cautious. My expectation is that we're going to check out sites and at least at first, initially sort of white-list them. So that "Ok, this site is the next one to receive Rich Snippets and this one is the next one."
But as we grow more confident that it doesn't hurt the user experience and that users like it, I expect us to continue to roll that out more and more broadly.
So there is documentation you can go ahead and read up on it and a lot of the Rich Snippets are of pretty understandable type. For example the number of stars on a review and things like that.
So you can usually get a pretty good idea of what your Snippet is going to look like, just from looking at what Snippets for other sites already look like. And that will give you an idea of what it will look like when it goes life for your site.