Microsoft has just spent a crazy-sounding 6 billion dollars on aQuantive, a company most people haven't even heard of, in a desperate attempt to keep up with Google and Yahoo! in the current frenzy of acquisitions in the online advertising space. Yahoo! acquired Right Media, WPP (a relatively low-profile* advertising services company) bought 24/7 Real Media, and of course Google started it all when it bought DoubleClick. The last remaining online advertising biggie, ValueClick, is like to be next, though it's uncertain who's still hanging around with enough money to afford the pricetag, which might be somewhere around $4billion (News Corp?).
Amongst other things, this ends any speculation that Microsoft might attempt to buy Yahoo!, since MS needed an online advertising arm and now they have one. And the price, while pretty steep -- close to twice aQuantive's market value prior to the announcement -- it's not completely crazy, since even at twice the acquisition price, aQuantive is earning something like 8 cents a share this year, which is definitely lower than the 11 cents a share Yahoo! makes, but not totally stupid (ValueClick is currently making 18 cents a share, so expect its acquisition price to be similarly inflated).
Microsoft is trying to reinvent itself yet again, under Ray Ozzie, this time as an open, web-based, advertising-supported company. Their embracing of the Internet in the late 90s was not a huge success -- it merely kept them where they were rather than pushing them forward. Will becoming a "web company" (whatever that means for a company that still makes the bulk of its revenue selling word processing and spreadsheet software) be any different? Online advertising is an explosively growing field, and one of the only technology fields where the numbers are big enough to make a genuine difference to Microsoft's bottom line.
But I don't see it happening. At best this will do as well as their Internet-focussing of the 90s did. At worst, they will find themselves a decade from now an irrelevant supplier of commodity operating system software in a market based on rich, server-side hosted applications running in whatever the descendant's of today's web browsers end up being.
* Update: some have pointed out that WPP is a gigantic company with a market cap well over half a billion dollars. It's not low-profile, it's just not well-known in the tech world, which is the only one I live in.