US consumers who purchase any new Windows Phone 7 will receive a free Xbox 360 game.
Microsoft launched the promotion to help drive sales for its new mobile operating system, which launched last month. So far, sales have been slow.
As part of the deal, gamers can choose from one of four titles: Kinectimals, Kinect Joy Ride, Fable III or Halo: Reach.
The offer is available with any Windows Phone 7 device, with Microsoft's official webpage highlighting the Samsung Focus and HTC HD7.
It also points US consumers towards the Buy One Get One Free promotions currently running at AT&T and T-Mobile.