[b1ake]

Actually there are no human teachers, the lessons are interactive and automated much like Codecademy. You're shown a few notes at a time and then as you play, the software detects each note and gives you feedback. There's also a virtual guitar mode so you can try it out without a guitar (it does require a signup though, at least for now).

[ScottWhigham]

That's good info - you need to have a "How it works" page rather than ask for the details before you share that. I love the idea though!