NPD said the MMO Warhammer Online: Age of Reckoning and Spore sold 274,000 and 406,000 units at retail, respectively, during the September retail calendar.
Warhammer Online released on September 18, while Spore launched on September 7 in North America.
NPD doesn't include PC games on its monthly top ten console software list. If they were, Spore would have ranked third after Wii Fit and Warhammer would have ranked seventh, beating out Wii Play.