Those ads are mostly on Amazon's automatic remarketing systems. They only recently opened up control over the bidding and targeting of those to sellers and bran

Those ads are mostly on Amazon's automatic remarketing systems. They only recently opened up control over the bidding and targeting of those to sellers and brands. Eventually considering how well that ad system tends to work in the right hands, I would expect it to be less intrusive and more effective over time. Amazon's remarketing tends to be paid for by Amazon and it behaves like any remarketing system run by other companies if you don't change anything from the defaults, set a very high frequency cap, and don't pay attention to whether or not the person converts.