Microsoft announced via a blog post earlier today that it sold a market-leading 1.7 million units of the Xbox 360 in December of 2011 in the United States. In 2011 as a whole, the Xbox 360 captured $6.7 billion in sales - $2.1 billion in console sales and $4.6 billion in games, accessories, etc. - and 49% of consumer retail spending. 

Microsoft also announced that it currently has more than 40 million Xbox LIVE subscribers worldwide, but didn't go into how many are actually paying for the service as oppose to those using the free LIVE Silver edition. 

The strong December capped an impressive year during which Xbox 360 was the fastest-growing console. It also captured 49 percent of consumer retail spending, with an industry-leading $6.7 billion in sales in the U.S. for the calendar year—more than $2.1 billion on consoles and $4.6 billion on games and accessories, NPD data shows.

Xbox 360 was the must-have gift this holiday season with about half of December’s retail spend on games, consoles and accessories going toward Xbox 360 products, totaling more than $1.5 billion, NPD data shows. According to internal Microsoft figures, the company has now sold more than 66 million Xbox 360 consoles and more than 18 million Kinect sensors worldwide, and has nearly 40 million Xbox LIVE members. 

The Xbox 360 now holds a commanding 46% market share in current-generation game consoles.