iPad 2: 500$+
Smart Cover: 40$
Evernote Peek: 0$.
Pack of index cards: 2$
How is creating a useful application for an expensive device that replaces an inferior took an example of excess? It's not really like people buy iPads simply to replace a pack of notecards and nothing else.
Also doesn't force you to lift up a magnet in meat space to use it.
If you do it every day you'll get amazing results, however I'm not that dedicated, but do it multiple times per week anyway.
Basically it makes my life a lot easier to have certain things memorized, and Anki makes memorizing stuff easier.
A lot of people (esp nerds) believe it is a sign of weakness to use flash cards. It's their loss.