"And wait a minute — didn’t I already pay for my iPhone? I gave $200 to Apple, and another $100/month to AT&T. Why does Apple now deserve additional revenue on an on-going basis just because I run apps on my phone? You might say, “but wait, Dave — this is designed to help developers continue to release free apps.” If that’s true, why are paid apps also allowed to use iAd? Mark my words — in a year or so, pretty much all apps will use banner ads. Not just free ones. Apple has found a way to turn their mighty iPhone into a ghetto of banner ads and reduced usability. Way to go, Apple. For the rest of us: My advice is to step over to a different phone before iAds melt your brain."

iPhone OS 4: Why It’s Time to Choose a Different Phone | Business Hacks | BNET

What ever makes people say such things and then bite their mouth does not make sense to me. I am not an apologizer for Apple and am skeptical about the iAd network. 

However, that’s more related to the apps themselves as Apple is not forcing any developer to adopt it. That said, if it will help Apple reduce a little more burden on the end user, I say - go ahead. I rely on the fact that Apple doesn’t hurt user end experience. And more than me, Apple relies on the fact that they give an amazing user experience. 

The minute they change that strategy, people will decide.