Google released a new product reviews update on 21 February. The update applies to 11 languages globally:
The announcement was made via Twitter.
Google’s product reviews system aims to reward high quality, in-depth reviews which provide “insightful insightful analysis and original research… written by experts or enthusiasts who know the topic well”. It is designed to weed out thin, low quality content which does no more than summarize products. This is the 6th update to the system.
The product reviews system primarily operates on a page-level basis, but if you have a large amount of product review content, the evaluation may extend to any page.
“…for sites that have a substantial amount of product review content, any content within a site might be evaluated by the update. If you don't have a lot of product reviews (a really substantial not-single-digit-percentage part of your entire site is made up of them), a site-wide evaluation is not likely to happen.”
***Update: Google said the rollout completed on 7 March, so now is the time to check if your rankings have been affected. If your site has been hit, it's worth revisiting Google’s Help page on how to write high quality reviews. Make sure you're in line with best practice, and make any necessary adjustments to give your site the best chance of recovering lost ground.