1. You bought the books fast/easy on Amazon... That is incredibly suspicious activity though, buying everything with different cards... You can get this fixed by dealing with Amazon support.
2. You bought them pretty fast/easy here too... Without knowing if you can transfer that format to your device.
Ehhh... OP is riffing on a theme that's been playing a long time.
Back around mid aughts, it was pretty easy to pirate movies. Doesn't really matter how but it wasn't hard (still isn't actually, but that's beside my point).
At the time I was still avidly collecting physical media, and I observed at some point, as did many others, that it became an absurd choice of getting an xvid, double clicking, and there's the movie, vs. load the DVD, sit through previews which, even if skippable, just no. And then the warnings of course, which again, sometimes skipping or fast forwarding would be disabled again.
So your reward for playing by the rules was wasted time looking at or skipping - forever - the marketing for whatever garbage they had coming out that season.
I understand that not everyone wants to embrace the Cory Doctorow professional model, but I sure don't mind giving him my money.
The goofiest part was how, often, one of the unskippable things making paid media worse was an anti-piracy notice! The only people to be pestered with them were those who'd paid for the thing—pirates never saw that crap.
2. You bought them pretty fast/easy here too... Without knowing if you can transfer that format to your device.
The title is misleading and inaccurate.