I can't remember which one, but a large shopping cart as a service provider does this (minus the discounts, or at least I didn't get them) for abandoned shopping carts where you've entered your email but didn't proceed to buy. Happened to me quite a few times because they only show shipping cost later on and they'd often be prohibitively expensive to ship to my country.

As for creepy: I wouldn't consider these creepy (i.e. where I've entered my email), but maybe annoying. I had the creepy experience with Pavlok when I first looked into getting one. Browsed around on their site but didn't put one into the cart. Hours later I get an email from them. Turns out they were using some service that loads a beacon and tries to connect the browser via various third party services to an email address. That was creepy. I still ended up buying a Pavlok though, but at a later time.