For those not in the know, Kart Rider is a cel-shaded racing game heavily (and we mean heavily) inspired by Nintendo's Mario Kart series. Players purchase upgrades and cosmetic features for their characters, and go online to race and compete. The Kart Rider client is completely free, and the developers, Nexon, earn all their revenue through virtual item purchases on the official site. The revenue model must be working for them, as Kart Rider is one of the most profitable games in South Korea, directly competing with Blizzard's mega-hit Starcraft. We'll have to wait and see if the game can make the same kind of impact in the States.
