On Friday I told you about Microsoft CEO Steve Ballmer’s riff on Bing and Yahoo. I asked him: How much market share do you need to gain in search to not need to do a deal with Yahoo ? Ballmer called my question “back-handed” and went on to give a really interesting answer. Check out the video or my Friday Postcard if you missed the Microsoft boss’s take on Bing and Yahoo.

Ballmer nobly engaged and sparred in our on-stage Q&A at last week’s Cannes Lions International Advertising Festival. He batted back my question about the global recession this way: “I don’t think we’re in a recession. I think we’ve reset. It’s very different. A recession sort of implies a recovery.” He added: “For planning purposes, I don’t assume there is a recovery.” Here’s more from Ballmer on the “reset” and how Microsoft is adjusting to it:

The Festival’s 2009 Media Man of the Year wasn’t afraid to sock the ad community with bad news. Ballmer proposed that media spending might decline as a percentage of GDP in the next 10 years. “We live in a funny Internet world,” he told the crowd of 1,000 or so. “As soon as all information and content is digital, and the marginal cost of production can look pretty close to zero, you get all kinds of changes in the monetization models.” Innovators will invent new ad-funded models, he said, “yet at the same time, the amount of time that people will be spending in relatively advertising-free environments could continue to increase.”

Not a happy outlook. Though, as I noted to Ballmer and the audience: Who can predict, really? I mentioned that I’d last been to this Lions Festival in 1993—and read aloud this prediction from a 1993 Fortune story titled “How Bill Gates Sees the Future”:

“I think the intelligent-corded phone will catch on faster than the PDA (personal digital assistant). We can take today’s office phone system with all those features you can’t figure out how to use and put a screen on it, and even do simple video conferencing. Also, in four or five years, you’ll have wild advances in flat-screen technology that will really change what makes sense to be on paper versus what makes sense to be on that screen.”

Ballmer’s reply to his famous partner’s outlook: “Well, he was right on 50% of the predictions!” Indeed, and the art of business is betting big on the right 50%.