I've always been stunned by how irrelevant the ads were on my Kindle, until I became so annoyed I paid the fee to turn them off. Ads for Kindle ebook titles I had already purchased, ads for household cleaning products, ads for books in genres I have never read (romance), etc. My spouse still gets them on their Kindle so I can see things have not improved one iota.

I actually found it a bit offensive, as in "how stupid do they think I am to be tempted to buy a book I already bought from Amazon", mixed with being puzzled and confused over why a company like Amazon would do such a disservice to its shareholders by doing advertising so very poorly and leaving money on the table.