Speculation is rife as to why Microsoft has decided to purchase GreenField Online, on online research company. The answer seems to be it that it was really after Ciao, a leading European shopping comparison website that has a large community of follower who shop and leave reviews on the site. This is due to the fact that Microsoft is really planning on selling off the Online Survey division (which incidentally contributes pretty much most of the revenue Greenfield makes) while retaining control of GreenField. They managed to beat another potential buyer (Quadrange) who also had their eye on GreenField.
This may seem strange, however when you consider that Microsoft is sitting on a massive cash mountain you can start to factor in that eyeballs are more important to them than cash. This acquisition gives them access to a European consumer market which they have struggled to penetrate. We’ll see how it pans out; some say that Microsoft will try and push their own products using Ciao, but I think they’re more interested in the audience than in promoting their wares. I would guess their first step would be to integrate Passport with Ciao to consolidate user identities across the two platforms.