Regardless, Microsoft’s not sweating it a bit. “We’re happy with the price we paid. We believe it’s exactly the right company to buy, so we’re willing to pay the value we are paying today,” said company CFO Chris Liddell during a call with analysts today. “We will use the strength of our balance sheet when we think it’s necessary to drive growth going forward. This deal takes our advertising business to a new level. This allows us to take a bigger piece of that $40 billion pie that is still growing.”

The WPP-24/7 Real Media deal follows Google’s recent acquisition of DoubleClick and Yahoo’s purchase of Right Media and puts to rest rumors that Microsoft was considering offering as much as $1 billion for 24/7 Real Media. Which begs the question: Has the software giant turned its attentions to aQuantive or ValueClick? Or has it concluded that there’s no reason to acquire an ad network when it already has a killer publisher ad server?

That scene springs to mind in light of reports that Microsoft, after losing DoubleClick to Google and Right Media to Yahoo, is mulling a $1 billion bid for online advertising outfit 24/7 Real Media (see “Takes a Convicted Monopolist to Know One? Ha, Ha, Ha. You Google Guys Are a Real Laugh Riot” and “What? You Thought Yahoo Was Going to Use a Google-Owned Ad-Serving System?”) Which is not to suggest that 24/7 isn’t a worthy acquisition target, just that Microsoft clearly hasn’t scored first choice in this little online advertising M&A dance. And, adding insult to injury here is the fact that this rumored bid for 24/7 is anything but a sure thing. WPP Group, the world’s second-largest advertising company, is also thought be a suitor for 24/7. Given its recent track record, maybe it’s time for Microsoft to move on and start looking at someone else. Like aQuantive. Or (smirk) Yahoo.