The NY Times solution, for example, is to target ads based on relevance to content on the page being delivered. No tracking required, but its relevance to the page can sometimes be more effective than tracking ads.
Conversely tracking ads are not necessarily smart.
Go shopping for a fridge, then buy one. You'll have fridge ads following you around even though you're not in the market for a fridge any more.
The NY Times solution, for example, is to target ads based on relevance to content on the page being delivered. No tracking required, but its relevance to the page can sometimes be more effective than tracking ads.
Conversely tracking ads are not necessarily smart.
Go shopping for a fridge, then buy one. You'll have fridge ads following you around even though you're not in the market for a fridge any more.