What's certain is that the advertising industry is evolving and growing at an incredible pace, moving increasingly toward online platforms. That movement dramatically increases the importance of software for this industry, according to Microsoft CEO Steve Ballmer. Today's announcement, he said, represents the next step in the evolution of Microsoft's ad network .

"Microsoft is intensely committed to creating a thriving advertising business and to partnering closely with all key constituencies in this industry to help maximize the digital advertising opportunity for all," Ballmer said in a statement. He pointed to MSN and the broader Microsoft network that includes Xbox Live, Windows Live, and Office Live as key components of the strategy.

Microsoft's Triple Play

Here's what Microsoft gets as part of the aQuantive deal: Atlas, DRIVEpm, and Avenue A | Razorfish. Atlas competes with DoubleClick. Its claim to fame is the Atlas Media Console, a toolset that offers agencies and advertisers capabilities to maximize ROI , and the Atlas Publisher platform that enables publishers to maximize monetization opportunities for their content.

Sort of like Yahoo's Right Media, DRIVEpm provides services to publishers and advertisers that match advertiser campaigns with publisher inventory. Finally, Avenue A | Razorfish is one of the largest interactive ad agencies in the world. The firm offers advertisers digital marketing consultation, media planning and buying, and creative services that help them use the online channel to build profitable relationships with their customers.

"The Microsoft-aQuantive deal is a triple-play because Microsoft gets DRIVEpm, which gives the company some long-term inventory it really needs," said Andrew Frank, a media analyst at Gartner. "Microsoft gets Atlas, which is the premier competitor to DoubleClick, and finally Avenue A | Razorfish, which gives them a platform to really get some traction on its SilverLight platform."

Monetizing Inventory

It should be noted, of course, that it's not as though Microsoft bought an ad server today. Microsoft bought a huge agency -- one that owns an ad server, said Nate Elliot, a senior analyst at Jupiter Research. That makes it different in his mind from Google's DoubleClick acquisition because DoubleClick is a pure ad serving play whereas aQuantive is an agency with an ad server play. For Microsoft, explaining why it owns an agency that competes with the rest of its clients could be interesting, he suggested.

Elliot said he finds the DRIVEpm aspect of the deal particularly interesting. "If you can build or buy a technology that helps you make more money from all those billions of ad impressions, then you stand to benefit," he explained. "Microsoft and Yahoo have both put serious efforts of their own to solve that problem. Now we see that they are turning to other companies to take them the rest of the way."

The deal is expected to be completed in the first half of Microsoft's fiscal year 2008.