In 2010 Facebook launched 'Places' - a feature that lets people announce their location to their friends on Facebook by 'checking in' to locations on mobile.
Using the (then) newly launched app we challenged fans to climb a virtual mountain by checking in to 'The North Face' stores across the UK. When a player checked into a store location on Facebook they climbed the mountain one step further. The first fan to reach the top of the summit won a truck of 'The North Face' gear!
The North Face in-house: Social