Sony Computer Entertainment says it's sold in 4.1 million PlayStation Move units since the device's launch two months ago. It's a slower start than Microsoft's Kinect -- yesterday revealed to have sold through 2.5 million units in 25 days -- but Sony says it's bullish on "momentum" for Move entering the holiday season. Against the overall install base of PlayStation 3, which Sony says now stands at over 41.6 million as of September 2010, it's a fairly small attach rate, considering that Move-supported games can use, and are in many cases aimed at, multiple players using multiple controllers. Conversely, an Xbox 360 unit requires only one Kinect device. The Move shipment figures do not include stand-alone PlayStation Eye camera or stand-alone PlayStation Move navigation controller shipments. Move launched September 15 in Europe, September 17 in the U.S. and UK, and on October 21 in Japan. Sony offered several bundle options for Move consumers, tailored based on whether potential purchasers already owned a PlayStation 3 and/or the required PlayStation Eye camera or not. The company soon revealed that the device sold 1 million units in the U.S. and Latin America in its first 30 days, and "in the area of" 1.5 million units in Europe. But as for its first 15 days, Gamasutra's Matt Matthews estimated that the device achieved an attach rate of only 1-3 percent of its addressable base. More than 30 U.S. games now support PlayStation Move, including Sports Champions, EyePet Move and SingStar Dance. Major first-party releases like Killzone 3 and LittleBigPlanet 2 are slated for Move support as well. [UPDATE: Sony Computer Entertainment America director of corporate communications and social media Patrick Seybold told Gamasutra in an email, "The 4.1 million units are global sales for the company." He added, "While we don't disclose our exact sell-through [to customers] number, the key is that our retailers continue to ask for more Move units and are taking every unit we can supply them with based on their sales and strong demand."]