Ask HN: What on Earth is going on with Amazon ads?

I was gifted a Kindle Oasis with lockscreen ads. The device is wonderful, though the ads have been misguided at best and real head-scratchers most of the time. Lately, though, they've taken a real turn for the bizarre.

Most of the ads I've been getting are for AI-generated children's bedtime stories with anime-inspired covers. Approximately 0% of my reading consists of bedtime stories, so this is odd -- and it can be a bit embarrassing when my Kindle is left on a coffee table -- though it's ultimately no big deal.

But I've been getting more and more ads that are just plain gibberish. Here's one example: https://i.ibb.co/5xdTJJh/IMG-4893.jpg

"Sleep. Unnllocking the seccelts fon restfulll nights."

How is it in Amazon's best interests to let gibberish onto their platform? Surely it would be a trivial problem to fix? And why are the "authors" paying for ads? What's the business model here? Self-contained AI marketplace?