[bluGill]

That only works if you actually click and buy. If you see an ad for a part you need, then go to hardware store and buy it they have no way of knowing that you saw the ad, much less how much influence the ad had.

It also fails to account for awareness being a major reason to buy ads. Ford want to advertise to everybody (probably including Amish) because most people will eventually buy a car, and it is important that you think Ford then. Even if you bought a car yesterday it is important to them that you not forget that you can buy a Ford - they know you won't buy for a few years, but they still want you to think of them.

[wesd]

Google has been trying to tie store purchase to ad impression [1]:

"This location tracking ability has allowed Google to send reports to retailers telling them, for example, whether people who saw an ad for a lawn mower later visited or passed by a Home Depot. The location-tracking program has grown since it was first launched with only a handful of retailers. Home Depot, Express, Nissan, and Sephora have participated."

[1]https://www.washingtonpost.com/news/the-switch/wp/2017/05/23...