Microsoft's slowly getting into the ad-supported software game for consumers and small businesses with its Live services. That might be a necessary strategy in the Google era, but chief software architect Ray Ozzie says software for big business is a whole different ballgame.At the Goldman Sachs Technology Investment Symposium this week, Ozzie reiterated the ad-supported vision and stressed how Google influenced Microsoft's decision to move into ads.

Except in software for big businesses. "Enterprises have a lot of complex requirements," he told investors. "And although some of the advertising might be able to be tactically used in certain products within that market, I think that's probably going to stay predominantly in the model that it is within."

It's an interesting point. One size doesn't fit all in the business world. Companies have shifting needs and shifting workforces. Presumably, workers don't need to be distracted by ads, either.

Yet it's not at all clear what specific "requirements" make it so an ad-supported model doesn't work in business, or what products Ozzie and co. will choose for advertising's "tactical" use there. I guess we'll have to wait and see; Microsoft's still in diapers when it comes to ad-supported products.