"Special offers"

OK, I gave up. I paid $20 to get ads for some "now playing" movie "by the author of the Twilight Saga" off my Kindle. If they were trying to get me to pay the $20, that's a very effective way to do it.
I heard from various quarters that the ads were often for useful stuff and were things you might want to buy, but in the week that I had them on, the ads were either not applicable to me or for stuff that varied between irritating and embarrassing to have sitting on my device.

I might root it now so I can put my own screens on it. EDIT: actually the default Kindle screens are very attractive. I'm fine with it the way it is.
I have one or two paperbacks from the brief period that publishers tried putting advertisements in paperbacks. The ads were on thick, glossy card stock, for brands of cigarettes that do not exist today. They were glued in so well as to make it likely to damage the book to cut them out.

Fortunately, the trend didn't last.

I prefer the Nook to the Kindle, due to ePub support, and the MicroSD card slot, not that the code behind that doesn't occasionally hiccup.

It's a shame that Barnes & Noble is doing so poorly in competition with the Kindle.
As I wrote elsewhere, file support is a complete non-issue, as is manufacturer. If you use Calibre to manage your titles, and as far as I know, there's nothing else that even comes close to being as good at doing it, it is completely irrelevant which device you use or what format your titles are in.

I had a Sony, then a Nook, then a Nexus tablet. I have a Kindle Paperwhite because it's the best reader on the market right now, and it does not matter even a tiny bit what format the files are in, really, who cares? It's completely transparent.

EDIT: as for expansion space, I figure 1000 books on the device at once is probably good enough. Even when I had the Nook with a card in it, I don't think I ever put more than about 100M of files on it. I don't really like keeping books on the device after I'm done with them, nor do I like keeping more than 2 or 3 months worth of future reading on the device, though given my reading speed, I could probably load more books on the 2GB device than I could possibly read in the rest of my life.

Edited at 2013-03-30 09:33 pm (UTC)
The SD card was a major blessing when my Nook bricked itself. I suspect pulling the battery would have reset it, but it was under warranty, so I just hopped over to B&N and they handed me a new one. Since I only put my stuff on the card, I just popped it out, and had everything I wanted on the new unit. No thought required.
That's definitely a benefit, but it's kind of an edge case. My Kindle got into a weird mood a couple of days ago, a 20 second hold-down on the power button fixed it.