Microsoft will buy a $240 million equity stake in Facebook
You can read yesterday's announcement that "the two companies would expand their advertising partnership and that Microsoft will take a $240 million equity stake in Facebook’s next round of financing at a $15 billion valuation. Under the expanded strategic alliance, Microsoft will be the exclusive third-party advertising platform partner for Facebook, and will begin to sell advertising for Facebook internationally in addition to the United States.
The transcript from the Facebook and Microsoft Expand Strategic Alliance Conference is pretty interesting too.
Manoj Jasra's blog includes some interesting statistics and commentary as does the bloggersblog which refers to an article in TheTimes stating that "Facebook has annual revenues of $150 million a year so the $15 billion valuation is 100 times its annual revenues"