Comment Because all purchases are done through one account (Score 1) 76
Plain and simple...
Say I have an Amazon account, and splurged for Prime. All purchases are going to go through me, even stuff I have no interest in and/or never searched for.
I do my searches, and order stuff; Amazon can easily track.
My wife does searching on a different computer, not logged into my account, then sends me an email saying, "Buy this."; Amazon has no clue.
A friend says they can't live without a product. I do all my research NOT on Amazon but on more informed sites. When done, I search Amazon via manufacturer part number, UPC, or ISBN. Amazon scratches its head how I got to a product without a bunch of page clicks.
A Facebook feed points to something useful on Amazon. I don't click on the link. I copy it, strip off the mile long of useless tracking codes, and paste in a link directly to a product to buy. Amazon claims witchcraft!
If I don't give Amazon data, there is not a lot AI can do.