It's pretty hard to do online ads without tracking because of how easy fraud is online. With newspaper, TV, and radio we put a bunch of effort into measuring t

It's pretty hard to do online ads without tracking because of how easy fraud is online. With newspaper, TV, and radio we put a bunch of effort into measuring the size of the audience, but those methods are far easier to subvert online. If I tell you jefftk.com has 10k daily active users so you should pay me $500 to put a banner on the top of my site, should you believe me?