I have finally gotten my campaign up and running but I have only one click in 48 hours. The same ad in Google would have 20 clicks by now. Is there a difference between Google and Yahoo searchers and ad copy they respond to?
I would expect lower PPC volume (at least that's been my experience) simply because Y has less volume than G. It's not necessarily anything to do with your ad copy.
The amount you get paid. More people use google plus the fact google allows more publisher which in the end generates more ads being sold. YPN should allow more applications to be easily approved.