Rapt is used by several top Web publishers to manage ad-inventory sales. It forecasts how much a publisher can get for ad placements, and whether they should sell the spots themselves or use ad networks. The company works with publishers like CNET Networks, Dow Jones and The New York Times. Rapt also helps Microsoft manage inventory on its own sites.

Rapt will be rolled into the Atlas Publisher Suite within the aQuantive business (which Microsoft bought for $6 billion last May). Rapt, with 85 employees, is a small deal that helps Microsoft fill out its technology checklist. With the recent conclusion of Google-DoubleClick deal, it looks like the massive consolidation of pure-play advertising deals is trickling down. (Quigo, bought by AOL for more than $300 million, was the last major exit). We’ll see more small technology acquisitions like this one, but for the big ad networks that didn’t get bought by now, their chances of a big payday going into a recession are slim.

Crunch Network: MobileCrunch Mobile Gadgets and Applications, Delivered Daily.