If Google is showing Rich Snippets, it doesn’t mean that other google algorithm thinks your website as a high-quality website.
We know how tough it is to get into the rich snippet. It is more difficult to maintain the result. But that does not mean, that all other Google algorithms think your website as a quality website. It just means that you crossed the benchmark of quality for your site to show rich snippets in the Google search results. Nothing else.
In a recent Google hangout, John Mueller reviled this. He was answering a question. The question was.
If my site regains rich snippets review stars, it lost them after a while. Does that mean from the quality algorithms, all the algorithms think that this site is awesome? Or can the site is hit by Panda or other quality algorithms even though it has regained rich snippets?
John replied to the question.
It doesn’t mean that your website can’t be affected by any other algorithms.
Essentially for rich snippets, we do consider the quality of the website to some extent. But we also consider whether or not these snippets are set up correctly, they are complying with our policies, all of that.
So, that is something that just because we are showing rich snippets doesn’t mean that we think that this website is above everything else, is fantastic and perfect. There can still be parts of the website where, our algorithms or some of our algorithms, are thinking, maybe this is something not so perfect.
So, it sounds like you are on the right track. But I wouldn’t lay back and say I don’t have to do anything more with my website. It’s perfect the way it is. And continue working on this. This is something, in general, all websites are dynamic and keep living so you can’t just stop working on it.
So, if you hear, if a site has rich snippets, it means Google thinks the site is high quality. I guess that is not 100% true.
Here is the video. You can find his response at the 9:42 mark.
You can read the forum discussion on Google+.