If I am on a tech site reading about disk drive failure rates, feed me an ad about an SSD sale. If I am reading about mountain climbing, show me ads about climbing equipment. Fine. But don't start following me around the web with adds about ascenders for the rest of the afternoon. Or travel insurance. Or ... It is none of your business what I browsed half an hour earlier.
Thank goodness at least one business (Apple) has enough customer focus left to try to address some of this nonsense. All the better that it helps them against some of their competitors. That just makes them more motivated. Bully for that. At least we are still the customers rather than the products with Apple.