Gabs at Cre8asite Forums noticed that just recently, Amazon has lost their rich snippets in the Google search results.
About a year ago, Amazon had rich snippets even without them adding the rich snippet markups for product reviews. Here was the screen shot back then:
Now, if you look, Walmart has the rich snippets but Amazon does not:
Now, yes, Amazon does not have any rich snippet markup on that page, as you can see over here. But they didn't have the markup last year either, Google gave it to them anyway.
Walmart does have the markup, as you can see over here but last year did not get the rich snippets in the search results and now does.
Gabs thinks there was a major change in the rich snippets this past week. He said a lot of his clients lost the rich snippets in Google.
Google did have a major rich snippet reduction in December 2013.
The Moz feature history tool doesn't show a major change in authorship or reviews in the Google results (note the top line is authorship and the bottom line are reviews):
Did you notice major changes in reviews rich snippets recently?
Forum discussion at Cre8asite Forums.