It's kind of like walking in a store, the sales person asking "what are you looking for", and then the sales person trying to sell you that thing you're looking for. This may be "insidious", but it's generally helpful for both parties. Google ads are usually the same way. Google knows what sort of things I want, and it reminds me from time to time. They make money, some random advertiser makes money, and I get the thing I want.
For me, it's closer to walking in to a library, the librarian asking "what are you looking for", and then the librarian trying to sell me that thing I'm looking for (which she gets a commission for).
