It has been over two years since Google initially introduced seller rating extensions, an advetising feature that provided merchants the ability to show their merchant star rating from Google Product Search within AdWords ads. 

The star ratings, which are/were aggregated from review site acros teh Web, enables searchers to find merchants recommended by users like them. This week Google unveiled a change to seller rating extensions that should spark some discussion. 

Google previously only showed the rating extensions for those that had at least 30 reviews and a 4-star average. Now, Google will only show the extensions for those with at least 30 reviews over the last 12 months and a 4-star average. Ultimately, this should better reflect consumer opions about a business and account for how it evolves over time.