Bloomberg: Wednesday, Facebook unveiled a new "Places" feature that lets mobile users check-in at locations and broadcast their location to their friends. The service works with existing geo-location services like Foursquare and Gowalla.
Analysts at Borrell Associates say the new feature could earn Facebook $4.1 billion in additional ad revenue by 2015. However, Altimeter Group's Susan Etlinger says the feature has big implications for privacy. It is Pandoras box when it comes to the cultural implications of this, she said. There may be a backlash. There may be people who are uncomfortable or unhappy with it.