I'd argue that this works only because there is a hard stop. A newspaper can not track you even if it wanted to. On the web, contextual ads is where everyone b

I'd argue that this works only because there is a hard stop. A newspaper can not track you even if it wanted to. On the web, contextual ads is where everyone begins as they "don't want to be evil". But ad monetized business models can make more money only in two ways - more users or more ads per user. Once you exhaust the first option for growth, the businesses inevitably pursue the second option because the web as a platform allows them to do that easily with additional tracking and data monetization, unlike with newspapers or radio. That makes this a 'soft' stop and the temptation has been proven too hard to resist for many, analogue to putting a jar of cookies in front of a child and asking them not to touch it. It would be much 'healthier' if a business model itself was not designed in a way that puts it potentially onto a trajectory to collide with user's privacy at some point in time.