Slight OT as it's more about ad-supported apps but... With "Today's News", we really struggled to make any reasonable revenue from mobclix, despite huge number

Slight OT as it's more about ad-supported apps but... With "Today's News", we really struggled to make any reasonable revenue from mobclix, despite huge numbers of requests. We understand from contact with mobclix support that returns are incredibly dependent on the ad format you use. Our app used mobclix in it's initial version but we've since moved to iAds (as an experiment as much as anything), which make more money. However the inventory is pretty narrow so despite a high CPM we still aren't making much money.