Don't misunderstand: this is a bad advertising practice. I don't like most advertising, relevant or otherwise, so if this happens as you describe then yes, the value add is negative. That doesn't make the data usage surprising though, and that was my point. It's okay if Amazon uses data I entered into search directly to advertise to me, even if they're not very good at it. Ethically, no line was crossed here.

What would be surprising (to most consumers) is if the Florida resort advertiser, instead of bidding on some broad target demographic, has access to enough data to target me individually. However that comes about, that is the line that is crossed. Why does the third party have direct(ish) access to this data? Why wasn't I informed? Etc. Whether that is direct sale of the data, or indirect targeting through unusually specific ad campaign targeting, the effect is the same: it's creepy.