If you look at anything anywhere on the Web, sooner or later you’ll see an ad for it — and sometimes much, much later:
I fervently wish that the advertising bots would realize that, once I’ve made an online purchase, I’m done. You can quit sending me info about wristwatches, I bought one. Don’t show me any other mattresses, I bought one (ask me how it was shipped, dayum I didn’t know you could do that). I bought a set of ATV tires, it’ll take years to wear them out, so leave me alone. I could continue, but I bet you know exactly what I’m talking about. You’re not really benefiting anyone by the deluge, so far as I see.
Then again, if the ad purveyors could actually know that you’d closed the deal, it’s also possible that certain individuals of dubious integrity also could know that, and could theoretically turn that knowledge to their advantage — though it’s probably more likely that their less technically-oriented peers would just break into the house.