iAd is one of the latest offerings from Apple for their huge iPhone developer base. iAd is simply Mobile Advertising through iPhone. This is a great opportunity for iPhone developers who develop free apps to earn some income even while their apps remain free.

Using advertisements has two parts: first, developing the advertisements for the iPhone and second, developing the iPhone application to show these Ads. Regarding the advertisements, these will be interactive as well as live (with videos, games, maps etc.) But the best part for developers is  the development of iPhone applications in which they can create banners to display these advertisements.

The selling and hosting of ads will be done by Apple. The developers can create applications using the classes and methods for iAds in SDK and allot space in the user interface to show these advertisements. Apple is sharing 60% of the revenues through such applications with developers. The model basically works based on the clicks and views of an advertisement through an application, similar to web advertising (note: Ad Sense).

The developer can use the ADBannerView class and its delegate methods to integrate iAds in their applications. They can allocate banner space of sizes 480 x 32 for portrait and 320 x 50 for landscape. These sizes can be achieved using the pre-defined constantsADBannerContentSizeIdentifier480x32 andADBannerContentSizeIdentifier320x50.The delegate methods like bannerViewDidLoadAd and didFailToReceiveAdWithError should be implemented to handle the various actions while an Ad gets loaded or a banner fails to receive an Ad.

iAds is a tremendous help to iPhone application developers to allow them to make money through facilitating advertisements through their applications. This model is expected to revolutionize iPhone application development.

Reference: For more details on ADViewBanner click here