Overall CC has generated lots of free exposure for GiftTRAP. We now get over 120,000 unique visitors per month. We would not have made the game a success without CC. — http://www.gifttrap.com/
GiftTRAP is a boardgame (with a variety of incarnations) that uses CC licensed photos within the game itself. Players exchange 'gifts' and each gift has a photo associated with it - most often a CC licensed photo found on Flickr.
GiftTRAP uses CC licensed photos from Flickr within their boardgame. These photos are used because they are open and free. GiftTRAP runs a contest on their website for people to submit their photos for inclusion in the next edition of GiftTRAP.
By using CC BY licensed photos, GiftTRAP is able to use a free resource to produce their game. This saves money, time, and promotes the commons.