While the advertising world buzzes about the possibility of acquisition of DoubleClick, the possibility exists that such a sale could sour current publisher deals, writes ClickZ.
Right now, for example, AOL uses DoubleClick for ad delivery on its network. That relationship was extended in 2005, with DoubleClick then taking over ad management on AOL Instant Messenger, MovieFone and other AOL properties. That relationship could end, though, if Microsoft were to buy DoubleClick.

AOL would obviously be loath to share its user data with a direct competitor such as Microsoft - or anyone else. AOL is another potential suitor of DoubleClick.

One of the most valued assets DoubleClick has is the cookie data that it has collected on vast numbers of online users. Access to that data by the buyer of DoubleClick is another concern of publishers.