The reading app is cloud based, unfortunately; you'll need a web connection to read the ebooks. Basically this means that you're paying an admission fee, not buying ebooks. Fortunately they already figured that out. You can't buy an ebook they're selling subscriptions ($4 a month or $40 a year).
There's even a free ebook for you to try. <- Could someone try this on an Pad and tell me how well it works? It's a pity that it requires Flash. I would have thought that it would be more likely that you'd visit with an iPad (or large tablet) than any other device.