Google+ (Google Plus) is using "like" & "share" button to get the actual stats about the popularity of the link. It’s exactly what “Butterfly” search engine is all about. We are glad that we thought it first.
Of course Google has done it the first time :P
If you click on “Spark” link on your Google+ profile page it shows news in different sections. You can always share & hit the like button. I’m sure Google will use these stats in their algorithm.