What Apple earns from iAds is chump change compare to Google's ad revenue. I don't deny iAds exists, but read my comment carefully. That's not their main source of income. Google's almost whole business is to sell ads. Apple can survive without selling ads, Google can not.
I just told you the difference. What is it that you don't understand?
Google's whole business revolves around showing you targeted ads. Apple's business is to sell you iDevices. Apple will not target you to the point where it's invasive and creepy (although I'd argue even the smallest amount of tracking is invasive, but I've been trying to look at this from Gabriel Weinberg's point of view) because Apple can not do anything to harm its main source of income. Google's job is to track you and they legally (and sometimes illegaly) do everything they can to be successful in their business. They can not hurt their main source of income by being invasive, because being invasive is their business.
For the record, I'm not saying Apple is any better than Google or vice versa. As I said, I've been trying to play the devil's advocate.
The point is, Apple does track you AND charges a premium. Google doesn't do both.
If you look at EFFF, Google has had your back longer with lobbywork before the EFF report came out ( https://www.eff.org/who-has-your-back-2013 ) as soon as that got popular last year, all of them upgraded their lobbywork (Apple)
Yes, now they all have 5 stars, but the EFF report first came out in 2011 without them knowing ( https://www.eff.org/who-has-your-back-2011 )... But there was a lot of hype about it last year, so they had to improve their "score-card".
Also, I doubt Apple would do something like Google's word gymnastics with the everchanging and murky ad profiling policy for student emails in the "free" Google Apps for Education.