The ads can be made relevant relative to website's content, not my previous activity. If I'm reading a tutorial on how to fix something there may be ads for too

The ads can be made relevant relative to website's content, not my previous activity. If I'm reading a tutorial on how to fix something there may be ads for tools that are required for that. This is very relevant to me and at the same time does not need any information about my previous browsing history or other activities. On the other hand, when I'm later visiting pornhub I'm unlikely to consider purchase of those tools even though they may appear relevant to my interests based on my previous browsing history. On the other hand, I am more likely to be interested in meeting hot moms from my area then - which is again solely context based.