I think what gtrubetskoy is talking about is Google (namely: search, Gmail, calendar, contacts, Plus--which are all tied to your Google account) and Facebook (namely: relationships, posting content, private messages, what you look at, etc) is information which is then mined or allowed to be targeted by advertisers for a handsome profit.

Apple doesn't do that. Their iAds are nothing in comparison to Google/FB's data mining. The only thing you get to go off of is the Advertising Identifier and the user can change/reset that at any moment effectively not tying them to any specific targeting.

I'm not sure what could be said of iCloud, but Apple itself isn't a big player in the ad-selling market unlike Google and Facebook. So unless Apple is straight selling off iCloud user data, it's a different ballgame.

edit: you also have to take into account Google and FB's ability to track you across the (near)-ENTIRE internet. Every FB/G-Plus share button, every video, image, asset loaded from FB/Google can track you via cookies. You could be reading a blog about pregnancies and how to prepare for a newborn on a cute little blog and Facebook may then target you for pregnancy/newborn products and services, etc. Unlike Apple, Google and Facebook aren't limited to their own properties in terms of info harvesting and ad-targeting.