Don't let that post confuse you. They didn't bother to read anything about it and just assumed the ads would be in the middle of the text.
This is perfectly sane. And for a bigger discount, I'd even consider one with ads in the middle of the text.
However, I already have a smartphone with the Kindle app, so it's hard to justify spending anything on another device to plug into the wall. (Especially since I don't mind reading on an LCD at all.)