Apple introduced its iAd advertising platform last week and SeekingAlpha.com is forecasting that iAd will earn almost US$5 billion per year in gross ad revenue, of which Apple will take a 40% cut at about $2 billion per year.

The financial webs site is also predicting that Apple will take a 30% cut of the forecasted $600 million revenues from paid apps in 2010. Last week, in introducing iAd, Apple CEO Steve Jobs said that, today, when users click on mobile ads they are almost always taken out of their app to a web browser, which loads the advertiser’s web page.

Users must then navigate back to their app, and it's often difficult or impossible to return to exactly where they left. Jobs said iAd solves this problem by displaying full-screen video and interactive ad content without ever leaving the app, and letting users return to their app anytime they choose.

He added that iPhone OS 4 lets developers embed iAd opportunities within their apps, and the ads are dynamically and wirelessly delivered to the device. Apple will sell and serve the ads, and developers will receive an industry standard 60% of iAd revenue.

However, Flash ads need not apply. They must be built with HTML. iAds can be designed by app developers as well as advertising agencies.