Both in the spirit of blogs taking over the known digital world (for the moment) and for the nice expression of what I think is at the middle of the stuff KPS folk are interested in, a nice quote from the creating passionate users blog.

The quote:

Learning is one of the fundamental reasons games are so engaging. For most games, the moment you have nothing left to learn is the moment you become bored and move on. Most teachers know that real self-esteem doesn't come from people thinking you're good at something... it comes from actually being good. Almost any activity gets better and better the more you improve, the improvement is nearly always a result of learning.

Musicians know this. Snowboarders know this. Programmers know this.

The more you learn, the better you are at something. The better you are, the more engaging it is. If you can help people have more of that feeling, they won't talk about how good you are-- they'll talk about how much they kick ass.

And that's a powerful formula for creating passionate users.