Don't stop behavioural ads...really
Let me state that I DO work around the edges of the ad industry, and I can tell you that most users BENEFIT from the best targeted ads possible.
Everyone wants free content and free services - be it YouTube, to CNN.com, to Picassa.
Guess what? That model is AD FUNDED. You get services on the web, or wireless mobile, and you get services/products/content.
How many free services/products/content do you get if there is little or no ad funding? A LOT fewer - you are currently getting a bunch now delivered to your screen that are exploratory at best - i.e., they are their in the HOPE that someone will make money by selling ads on them in the future. But very few of them actually ARE right now - in part because ads on the web and ads on mobile are not well targetted at present, and therefore advertisers pay a lot less for them (not in aggregate, as online advertising is now the #1 medium, but for EACH page impression or clickthrough rates are very, very low).
Eventually, this Web2.0 boondoggle will end, just like Web1.0 boondoggle and all the free sites not making money lost their financing. Whatever services you still have access to will be the ones that can actually MAKE MONEY by selling ads - enough money to make it worthwhile, including profit.
Behavioural targeting can increase the revenue from an ad by up to 50%+ - meaning that there is suddenly a LOT more money around for ad funded content and services. ANd that can lead to an increase in the amout of ad spending online and mobile can get from advertisers, rather than having them spend it on direct email campaigns, magazines, etc - which you get no services in exchange for.
So there is your choice - make targeting opt-in (which almost NO ONE will do if they have to sign up for it), or get ready to start seeing a lot of ad funded stuff dissapear. Some still will in the upcoming rationalization, but a lot fewer if we can claim more revenues from advertisers.
That's simple economics, and anyone who doesn't see that has their eyes closed...