A Facebook spokesperson discussed this test with TechCrunch:
We’re extending star ratings on Facebook from mobile to desktop – to make it easier for people to discover great businesses around them. This is beneficial for both businesses and consumers. Star ratings encourage more people to rate a business, making it eligible to appear in News Feed and help others discover a business they didn’t know about previously. For businesses themselves, this also leads to greater brand awareness.
As you may recall, star ratings launched in early 2012 with the introduction of Nearby on mobile. Now we’re bringing the visibility of star ratings to a more prominent spot at the top of Pages’ timeline on desktop and to the preview in News Feed.
Readers: Have you seen this?