As a developer I prefer iAds over other networks even though I use others also (as a back-up).
I've found that the lower tier developer iAds (advertising app store apps) bring in more revenue to developers than say adMob, mobFox etc.
The top tier full iAds tend to bring in 10 times the revenue of the lower tier per impression iAds.
The problem has always been inventory availability.
If Apple can sort the inventory then there'll be no reason to use a...