5% of people who click on a YPlan mobile app ad in Facebook buy tickets

"In addition to helping YPlan acquire new customers, Facebook mobile app ads are part of YPlan’s full customer lifecycle. Mobile app ads for engagement and conversion have proven to be an excellent way for YPlan to interact with their existing customers and app users by engaging with them with specific and relevant events.
1 in 20 people that click on a mobile app engagement ad purchase an event and YPlan has seen a 20% increase in paid bookings through mobile app engagement ads. Thanks to mobile app ads, YPlan has seen a 215% return on investment for engagement ads.
The YPlan team works with many event planners, so it suggests different events to specific audience segments. For instance, if a Beyonce concert is coming up, YPlan targets her fans with its advertising, getting improved cost-per-click results."
Source:  Facebook's Developer Showcase, retrieved 7th October 2014