About a month ago we heard that Microsoft and Google were fighting over who got to take Facebook to the prom. Or to put it more precisely, the companies were in a bidding war to buy a 5-10% stake in the social networking site.

Now the New York Post reports that a deal could be announced within the next day or two. Last month Microsoft offered to pay $300 to $500 million for a 5 percent stake, which would value Facebook at $10 billion. The Post claims that Google has been driving the price up closer to the $750 million Facebook has been seeking.

Now here's where things get a bit more interesting. The only reason either company cares about Facebook is because the site has a huge user base and valuable demographic data. In other words, it's a potentially rich source of advertising revenue. The Post says Google would probably try to kill Facebook's ad deal with Microsoft, while Microsoft would expand its partnership.

But Facebook is also preparing to launch its own advertising network next month. Would a partnership with Microsoft or Google kill that? Or is the reason they're willing to spend so much money on a 5-10% stake because they've already seen the new ad platform and plan to integrate it with their own?