I do not know a lot about the ad mechanism, which my partners use. But it usually works by contacting several servers and asking them "hey, there is someone visiting www.Photopea.com, probably from Canada, with a screen resolution of 1920x1080 pixels, how much would you pay for showing them your ad?" ... there is an auction, and the ad from the highest bidder is shown to you. The more servers take part in the auction, the more money I can make.

Like really, if you open a website for the first time in your life, what kind of secret information could it know about you?