$100 bills lying around, why's nobody picking them up?
The New York Times has an article on the glut of energy efficient opportunities around us and it makes a pretty convincing case. So the question with so much free money available, why don't people take advantage of it. Says a lot about inertia is my guess. If a light bulb is working, why replace it. And you pay your electricity bill because you have to, it hurts but when you write the check. You forget the pain and move on.
So the goal is to make sure that people don't have to think about taking advantage of efficiency. They just do it since all choices available are efficient.