Re: Accurate Ads
That's not actually true.
At least in TV advertising the channel only gets paid for the proportion of the viewers in the demographic that the advertiser are targeting.
This is also true in 'static' advertising. The Register is likely to get significant higher revenue per user if they can show 80% of users are IT professionals and therefore in the target audience. If another advertiser is targeting IT students then they might only pay 10% of the price to cover that 10% of the audience. 100% accurate targeting would allow ElReg to get both sets of revenue at the same time - by showing the 10% of students the adverts for the company wanting to target students, and the 80% of IT professionals the ads from the company only wanting to target IT Professionals. The other 10% might be randomly distributed and they effectively wouldn't get any money for those users