Microsoft came out with its new motion gaming peripheral, the Kinect, on November 4 to sell 5 million units by the end of the year. Approaching the midpoint of its time frame, Microsoft announced today that it has reached the midpoint of units with 2.5 million units sold in 25 days. Previously, Microsoft announced that Kinect had moved 1 million units in 10 days. This means that Kinect is selling at a constant rate of 100,000 units per day.

GameStop and Target reported that the Kinect was a big Black Friday weekend item, generating a lot of business on Black Friday and throughout the weekend. Both companies said they expect the Kinect to continue to be a “must-have” item during the holidays and that while they both expect a steady supply from Microsoft, they will simply have trouble keeping them in stock on store shelves.

Microsoft’s Kinect peripheral is a new device used to complement its current video game console, the Xbox 360. The device allows users to control Xbox 360 and Kinect-specific games without the use of a standard controller, rather than using their body as controller. The Kinect comes with voice recognition capabilities, facial recognition, 46-point skeletal tracking, auto-adjusting motorized base to follow left and right used around the room, and the ability to issue a series of voice commands.

Kinect launched with 17 launch titles, many of which would be classified as “casual” software. Microsoft has been very open about the Kinect being a device to appeal to the large, previously untapped casual market captured by the Nintendo Wii over the last four years. The casual market refers to the segment of users who did not normally play or had minimal experience with video games before the latest generation of video game consoles.

While Nintendo isn’t seen as competing with Microsoft or Sony due to its different customer segments, Microsoft is looking to encroach on Nintendo’s turf in hopes of doing something Nintendo hasn’t been able to do with the Wii: turn casual gamers into mainstream gamers.

While Nintendo enjoys a larger install base than Microsoft and Xbox 360, Nintendo has struggled when it comes to consistent software sales, especially when it comes to titles created by third parties. In other words, Nintendo may sell the system, but Wii owners are unlikely to regularly buy software for the console. This has led to a massive abandonment of third-party developers to create quality games for the Wii, citing poor sales on the console with cross-platform titles. On the other side of the fence, Microsoft sees its relationship with third-party developers as one of its biggest competitive advantages, and is doing everything it can to help developers create entry-level and casual games for the Kinect.

As Kinect appeals to the casual crowd, giving Microsoft a larger install base, the hope is that those customers will want more complex entry-level games. Microsoft believes that it can have the best of both worlds and make those worlds collide, se and kinect.