Amazon presumably doesn't share purchase history with advertisers; you get lumped into a cohort with certain interests/keywords. An experiment to try; if you o

Amazon presumably doesn't share purchase history with advertisers; you get lumped into a cohort with certain interests/keywords. An experiment to try; if you only go shopping/searching for vacuum cleaners but don't actually buy one you are likely to see the same phenomenon. Why do advertisers pay for this? Because conversion statistics show that showing ads to people shopping for vacuum cleaners do actually result in vacuum cleaner sales. A/B tests back up the causality of the results, so vacuum sellers pay for the ads. Why doesn't Amazon remove you from the cohort of vacuum cleaner shoppers after you make a purchase? 1) it would reveal that you made a purchase. 2) Amazon would lose out on additional ad revenue. I have no inside information on Amazon but it matches what I've seen on other large ad networks.