50% is large for a web-based ad network. Unless they're highly verticalized or doing direct sales (and therefore have less competition), 20-30% is more reasona

50% is large for a web-based ad network. Unless they're highly verticalized or doing direct sales (and therefore have less competition), 20-30% is more reasonable. AdMob (Branchr also does iPhone ads), for example, has a default 60/40 split in favor of publishers. That's the ceiling -- it will be lower for people they want to keep as clients (i.e., clients with leverage). They're also the #1 mobile ad network, so smaller networks will have to be more publisher friendly than they are. For my FB properties, I have most of the ad networks I work with negotiated down to the 10-15% range.