ZeRaW wroteI see e-commerce, did you know you cannot sell from you iphone/ipad/ipod (iOS) app without apple having 30%?
If you do not want to pay apple 30% on EVERY transaction forget about iOS app.
it's the same in Android,"Application developers receive 70% of the application price, with the remaining 30% distributed among carriers and payment processors (Google does not take a percentage)" (the source is Wikipedia)