This Danish company  was looking for good front-end developers. Of course these guys like to play games as well, so they started an in-game promotion with posters in the free online game Team Fortress 2. Check the video to know how it worked and how many applications they got!

Of course the american army has been doing so since 2005 and it has proven to be their most effective tool to find new recruits! You can read more about that on my blog here: http://gamingandbranding.blogspot.nl/search?q=america+army