A few weeks ago, Microsoft paid $1.05 billion (USD) for approximately 925 of AOLs patents (and patent applications), acquired a license to the 300 AOL did not sell, and got some stock of an unnamed AOL subsidiary out of it. AOL gets to keep a license to the sold patents, as well.
Microsoft has now turned around and sold approximately 650 of those patents to Facebook, retaining license rights, for $550 million (USD). They have also included licenses to the other 275 that Microsoft is retaining.
The biggest question is What The Heck Is In These Patents???
Source: Microsoft News