Kiip is a mobile rewards company that allows advertisers to give awards to their customers while they are interfacing with games or apps. The Kiip system shows banner ads at a moment of achievement within an app. Users who click on the ad can claim a reward, like a $5 shopping card from a retailer. (See the above picture for an example.) Currently Kiip is in the process of expanding its model beyond mobile to any web platform.
BTW, according to its web site, the company name is pronounced "keep," not "kip."
Learn more about Kiip in this article from VentureBeat.