[thomasilk]

It's not hard at all to exclude buyers of the advertised product from the ad and I can't imagine that Amazon doesn't know that. We're doing it for clients all the time.

Probably they just don't care enough about their ads being a few percent more efficient as long as they are profitable.

[shostack]

Have you actually managed ecomm campaigns where you've done this? If so, how were your tags set up to facilitate this, particularly solving for the obvious cross device challenge?

I'm genuinely curious because those of us that are experienced in the hands on management of this stuff know how hard of a problem that can be in some circumstances.

Fwiw exclusion lists can be very effective if you can properly cookie someone at the appropriate time or leverage a data broker to pipe in CRM data. But it is by no means an easy thing to solve for.