said 11 months, 3 weeks ago:
The “promote” option just popped up on our page today. I paid $10.00, which translates into an estimated reach of 1,700 fans.
The feature is actually pretty neat: you get to see how many EXTRA people saw your post as a result of the promotion, and what those people did (e.g. viewed one of the tabs that my post is directing people to).
Additionally, Facebook is now showing the number of people who see your post directly underneath the post itself, along with what percentage of your total number of fans that is.
So far, pretty pleased with this feature.