There may be value in that, although is it not mostly for them? Once the book arrives and you recognize you've already read - you return and that's at Amazon's expense.

I highly recommend you do a personal information request from Amazon.. there is an astounding amount of data in there. Companies that have bought you as an ad target, Alexa/Ring/Music/Smile/AppStore/PrimeVideo interactions, including country/IP requested from (why can't you see what you've watched in PrimeVideo and/or hide it? They clearly have the data), every credit card/address/coupon code you've ever used. Everything you've ever searched for (by far the largest file).