What's hindering someone else? I'm not talking about ads only, but also search. Google brings customers without the business having to pay anything to anybody or suck up to industry cartels.

There's a meme that ads must be based on covert tracking, and google analytics being everywhere is the most powerful covert tracker, also built into Chrome.

I think ads using tracking are close to worthless and that the whole Analytics/ad industry is just busywork that makes people think they're doing something important. Especially Facebook are good at luring small businesses in and convincing them to "keep trying" with different demographics and parameters to spend more in ads.

I never understood why more businesses don't use discount codes to know where their marketing is having an effect. That's ground truth.