Are we to praise Steve Ballmer, or bury him?

Oh, what the heck, let's do both. Though we'll go light on the praise part. Because Microsoft has proven itself to be horrendous at this whole M&A game.

Microsoft-Yahoo won't happen, and it was never a good idea -- not at forty-something-billion dollars. Megamergers are never a good idea. They are for the desperate and the contracting industries. Synergies are a laughable concept. Anytime some CEO promises synergies in a big merger, think of it in the same category as a washed-up TV star on an infomercial telling you that some product will make you look like an Olympic triathlete in two weeks.

Who knows what was actually going through Ballmer's head, but he behaved like a guy who had second thoughts a week before the wedding. He seemed to want out. Seemed to realize buying Yahoo wouldn't be all he'd hoped it would be and may have turned into a disaster. The price difference looked, in the end, like a convenient excuse to call it off and save face.

Which took more guts than actually going through with the deal. Good for Ballmer. Good for Microsoft. Have a beer with the boys and go back to playing the field.

Now for the burying part...

Microsoft has about $40 billion in cash, and for the past decade it has always had that kind of whopping bank balance. It has been in the driver's seat for acquisitions for as long as the Web has been a significant industry. But what, in the purchases department, does Microsoft have to brag about? Well, there's Hotmail.

Microsoft bought Hotmail for $395 million in 1997. It vaulted Microsoft into the just-emerging business of free email, and made Microsoft look smart and hip. It was the first and last time that would happen.

Look at Microsoft's other big Web purchases. In 1997 it bought WebTV for $425 million. The company made a box that put the Internet on TV. Last I looked, just about nobody anywhere is surfing the Internet on TV.

In 2000, Microsoft paid $1.4 billion for small business software company Great Plains. From what I've heard, that never worked well and didn't help Microsoft much in the small business market. Microsoft has made only two other acquisitions that are known to be above $1 billion. It bought Danish company Navision for $1.45 billion in 2002 -- now turned into Microsoft Dynamics, which may be an OK business but nothing to make shareholders dance a jig. And then in 2007, Microsoft bought online ad agency aQuantive for a whopping $6 billion. We'll see how that goes.

Some think last year's acquisition of Tellme for $800 million will prove smart. Oh, and in 2005 Microsoft paid $125 million for Ray Ozzie, which has worked out well. On paper, Microsoft bought Ozzie's Groove Networks, but the prize was Ozzie.

The more fun exercise is to look at all the opportunities Microsoft has missed over the past decade. It could easily have been the one to buy MySpace at an early stage, instead of seeing News Corp pick it up. It could've grabbed YouTube instead of letting it go to Google. It might have bought or invested in Yahoo when that company was just taking off in the mid-1990s. How about Adobe? Six Apart? Flickr? LinkedIn?

A lot of reports today speculate on who else Ballmer will buy now that Microsoft is free from the Yahoo deal. If history is any guide, he won't buy anything good.