I'm not sure that things like Amazon's "Customers who bought
this also bought
that" is particularly amazing or clever; that ain't rocket surgery, you know! Sure, every once in a while I'll go "Yep, I probably need me some of
that, too", but mostly it's "Nope - I've already got plenty of
that, thank you. Moving on ..." And like everybody else, I too get sick of being pitched even more of
this, or different variations of
this, after I've already made my purchase. I'm sure that all of it does lead to at least an incremental increase in sales, though, so it serves its purpose.
A while back I saw an article on the success of an "A.I." that was being used for marketing purposes. And as I read through all of its supposed "breakthrough suggestions" I thought to myself "You know, you could have saved yourself an awful lot of time and trouble and money if you'd just read pretty much any sales and marketing book from, say, the last 100 years or so." Because there was really nothing there that wasn't already pretty much common knowledge within that realm.