Microsoft is at the top of the financial news this morning by announcing it will buy online advertising firm aQuantive Inc. for a staggering $6 billion. The deal will see aQuantive receive $66.50 a share in cash, an amount 85 percent higher than the stock’s closing price yesterday. The offer dwarfs the earnings forecast that AQuantive anticipated for 2007: the company had predicted it would bring in about $70 million in net earnings, up from $54 million in 2006.

While most of the media seems focused on how this move is in response to Google buying up online advertising company DoubleClick last month for $3 billion, what interests me more is what this deal means for Yahoo!. I had written a lengthy feature article when news broke that Microsoft and Yahoo! were back in merger talks a couple of weeks ago. Seeing how Yahoo! recently nabbed the remaining portion of online ad firm Right Media that it didn’t already own for $680 million last month, I’m wondering if this mean the tempestuous love affair between Microsoft and Yahoo! is once again off. And if it’s not, how would they utilize their respective investments in online ad firms were they to combine forces?

With nearly $7 billion worth of acquisitions happening in the last six weeks or so, there’s no doubt that online advertising is the place to be. How to take advantage of this major shift in the online ad industry is a different story. Seeing how I’m a bit short on original ideas myself, I thought I’d leave you with this hilarious spoof on viral marketing.

(And yes, I’m aware that this post totally gives away the answer to question 6 of this morning’s weekly finance news quiz. Consider it a freebee.)