Disclaimer: I hate Google Analytics because I hate Google, I hate monopolies, and I hate excessive hoarding of user data. I think the necessary aspects of tracking can be maintained without having all the bad aspects, but we need to break up the ad companies first.
> without watching exactly how every customer looks at shelves
This is absolutely not true. Do you have experience with managing brick and mortar stores? Ever been to a grocery store with a "discount"/rewards program? That's their tracking of individual behavior.
They also use credit card data for the same purpose, although CC data is less reliable than rewards cards.
Coupons accomplish the same thing. You put out a specific coupon code for each newspaper/circular/TV ad, and then you see how they convert.
Things like Google Analytics are just the web version of things that have been done for almost 100 years.
> without watching exactly how every customer looks at shelves
This is absolutely not true. Do you have experience with managing brick and mortar stores? Ever been to a grocery store with a "discount"/rewards program? That's their tracking of individual behavior.
They also use credit card data for the same purpose, although CC data is less reliable than rewards cards.
Coupons accomplish the same thing. You put out a specific coupon code for each newspaper/circular/TV ad, and then you see how they convert.
Things like Google Analytics are just the web version of things that have been done for almost 100 years.