Microsoft COO Kevin Turner just dropped a bomb on the assembled audience at the Worldwide Partner Conference -- the company will open 75 more retail stores in the next two to three years.

That's a really smart move, particularly to help Microsoft sell more Windows Phones. The company has had problems getting mobile carriers to push its phones over the iPhone and Android models.

It could also help Microsoft Windows 8 tablets when they start to emerge in 2012, and push entertainment products like Kinect and Xbox Live.

Earlier this year, we heard that Turner and CEO Steve Ballmer wanted to accelerate Microsoft's retail push, but were hesitant because it would increase Microsoft's capital expenditures and the current crop of stores weren't making enough money. Apparently they decided to bite the bullet and push ahead anyway.

Based on a map Turner showed at the conference, a lot of those stores will be concentrated in the Northeast -- an area where so far Microsoft has no retail outlets. He also said that Microsoft will build stores outside the U.S.

Right now, Microsoft has only 11 stores, with five in southern California. A twelfth store is being built in Seattle.