Microsoft&39's Kinect: A million sold.

The million mark is a big milestone in sales, and today Microsoft announced that its Kinect system has joined the list of products to get there in short order.

The $150 motion control camera accessory for Microsoft's Xbox 360 landed on shelves in North America 10 days ago and in Europe just last week, and, according to Redmond, it has just hit that magic million number. Microsoft says that puts it well on track toward reaching the company's estimated 5 million units by the end of the year.

One thing Microsoft is not saying is how the million unit numbers are broken down. Currently, the Kinect sensor is available in three variations: just the sensor with a pack-in game, and included as part of a 4GB or 250GB Xbox 360 console bundle.

Citing retailer reports last week, Dennis Durkin, corporate vice president and chief operating and financial officer of Microsoft's Interactive Entertainment Business, said that the units were being sold just as fast as Microsoft could get them manufactured.

Kinect, which formerly went by the moniker Project Natal, made its debut at 2009's E3 in Los Angeles. Its big differentiator from competing motion control systems on Sony and Nintendo's game consoles is that it does not require the use of a controller. Instead, it uses multiple cameras and microphones to track motion and user voices, which can be used to control games and low-level system functions.

Kinect is slated to hit two more markets later this week, including Asia on November 18, and in Japan on November 20.