Microsoft Corp. (NASDAQ: MSFT) completed its largest-ever acquisition this past summer, ponying up over $6 billion for internet advertising technology firm aQuantive. What happened here was simple: Google beat everyone to the gate for purchasing DoubleClick, arguably one of the largest influencers in internet advertising outside of Google's own kingdom. Was the aQuantive buy a knee-jerk reaction to Google's DoubleClick acquisition? To many, it was.

But now that the sting has passed, Microsoft CEO Steve Ballmer says that the world's largest software company wants to go after as much as 20 smaller acquisitions (priced from $50 million to $1 billion) instead of the next mega-billion-dollar deal. Although Microsoft has over $23 billion in cash and marketable securities on its hands, it still needs to watch which cookie jars it dips those golden hands into. In other words, no more knee-jerk reactive buys.

Is Microsoft, then, out of the running for competitor Yahoo, Inc. (NASDAQ: YHOO)? Probably, as the on-again, off-again talks between the companies (even if they both deny it) are probably gone for good. Ballmer may be playing his trump card when stating the company will focus on smaller acquisitions. All Ballmer is saying now is that Microsoft is focused on an "independent path" of acquisitions. Is this smoke and mirrors or the truth? Whip out that crystal ball and see if you dare. My guess: he's telling the truth, even as rumors swirl that Microsoft plans to take a 5% stake in Facebook.com.

Reports today suggest Microsoft (NASDAQ: MSFT) is poised to launch the next salvo in the scramble for vertical integration of the digital marketing industry by purchasing 24/7 Real Media Inc. (NASDAQ: TFSM). 24/7, whose ticker symbol is coincidently the mirror image of Microsoft's, provides e-marketing strategies, analytics, search marketing and campaign management. Its client list includes British Airways, Forbes.com, United, and Playboy.

If it buys 24/7, Microsoft would join Google and Yahoo in positioning themselves to provide advertisers with a one-stop shop for content, ad opportunities appearing on that content, campaign design, management and measurement. For example, Google offers content on, among others, Search and YouTube, while its AdWords and recently acquired DoubleClick manage the sale and placement of ads on its content.

According to the New York Post, the current asking price for 24/7 is $1 billion, no doubt boosted by Google's recent purchase of DoubleClick. Last week, the New York Post reported that advertising giant WPP Group (NASDAQ:WPPGY) was also considering a purchase of the company.

These are fat times for companies in the internet advertising delivery stream. Look for more to cash in while the market exuberance is high.