Is it legal to display ads in an iPhone app without using Apple's iAd system

Is it legal to display ads in an iPhone app without using Apple's iAd advertising system? Is it still legal if I am compensated for displaying those ads?

I have asked on the official Apple forums but have not gotten a good answer.

Thanks开发者_开发技巧!

Yes, it is perfectly legal. Lots of apps on the app store use ad providers such as AdMob etc. but the reason that iAds are most often used is that they get the most revenue on average.