I cannot understand the problem in just showing ads based on the content of the website I am visiting. You don't need to spy on me to realise that I am interested in needlework if I am on a site called threadsandneedles.com

Meanwhile the ads that do track me are annoying as hell and frequently show shit I am not the least interested in (Facebook knows I work in IT, why my timeline isn't full of cool as hell gadgets I will never know).