There continue to be conflicting views as to whether iPhone developers actually make money from ads on the iPhone. One issue is that free app developers who advertise in games end up paying on a CPC basis, in which the click takes the visitor to the App Store. But often times the actual download doesn't take place, so the developer is left paying for clicks that don't produce conversions, says mobile game advertising network Greystripe. Now the network is changing its ad network economics around to help developers mitigate this issue. Greystripe is offering a $0.99 per download program available today to guarantee iPhone application developers downloads of their free apps. Of course, this comes with a catch. Greystripe is offering download program to publishers who spend a minimum of $10,000 and is being offered on a limited basis to the first 200 developers who apply. The first 100 qualifying developers who email techcrunch@greystripe.com will gain instant access to the program.