Those lovely stars showing up in the SERPS…. just might be fading away…. starting on February 15, the number of queries that returned results with review snippets has dropped by roughly one third. Barry Schwartz at Search Engine Land posits that this may just a bug, not a feature change and Google hasn’t responded to questions about it. Furthermore, I can’t imagine reviews are going to decline in impact for local results AND asking your customers to crow about you online is still a best (marketing) practice – so I wouldn’t change anything at the moment.
Here’s the drop-off visually from Moz’s SERP feature tracker:
UPDATE: Looks like this was indeed a bug over at Google: