I think what OP's referring to is forms of "targeted up-sell", where they could choose what kind of fishing poles to sell to you. Here, the deal might be a favourable one, but not for you (but for the sellers of course).

There was that (in)famous NYTimes article from a few years ago about how the target supermarket was successful in finding out a teenager's pregnancy before the girl's father did, and sent her coupons for baby items (which is how the father first got wind of the likelihood of his daughter's pregnancy).

So, as the OP says, it gets murky and grey very quickly as you get into "personalised" selling.

We "live in interesting times" indeed.