The ads that appear here are mostly from Google, but "tracking cookies" that you pick up when you use Google or when you visit the majority of "commercial" sites may be used to "target" which ads a given person sees.

There is some evidence that the ads you see may be based on "what your friends" have looked at, if you're into social networking (Farcebook et. al.)

As noted in another recent thread, when you tell us what ads you see here, we can infer "what you've been doing" and if that doesn't fit we can guess what kinds of "weird friends" you have. (Most of us are too polite to spread rumors about our conclusions, but there might be some nominal risk.)

Ads for "professional employment" might come just from you having a subscription to a magazine related to a particular industry, such as oil .... Lots of "old timers" continue such contacts well after retirement, and everyone's subscriber list is for sale somewhere.

About the only ads I get that aren't related to recent searches are from people wanting to sell me "final expense insurance" to make sure I can pay for getting "planted." ... (Makes me wonder if my doctor has been leaking my medical records.(?))

John