I probably could have told you this one based on the anecdotal data I've heard from developers lately, but "insiders" have told MobileCrunch that Apple's iAd service isn't doing quite as well as Apple had hoped. The fill rate -- which refers to actual ad space that's filled with a paid ad -- has dropped from 18% to 6% according to the rumors, which means that even though Apple has developers ready to show ads, it's having trouble actually finding advertisers to pay for them.
As MobileCrunch notes, even if this is true, there could be a few reasons for this, from a bad economy to just a bad seasonal trend (that could pick back up as so
