Initially, AdSense &quot;served ads that related contextually to the content on a web page&quot;.  (text-only, non-invasive ads, fair revenue)<p>What you nowadays mean with AdSense, the ads that follow you around (tracking, little revenue) started in 2009&#x2F;10: &quot;Google AdSense started using search history in contextual matching to offer more relevant ads&quot;. [my pov: this started a new Ad Tech boom which is now again on a tipping point and waiting for another disruption - because site owners get little revenue and it sucks for end users (crash browsers, drain batteries, too invasive, already own advertised the products)]<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Adsense#History" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Adsense#History</a>