I wouldn't be surprised to find out that other people do it as well. The cleverness of it is that it appeals to people who are lazy (like me) and don't want to follow a regimented personal accounting system, while being fairly bulletproof and without having to think as much about where your money goes. It sucks to be a penny pincher who follows every dime, and I have my doubts that that level of attention has returns that warrant the effort. I'm actually pretty savvy with money, but over the years I've found that this method easily gives some of the best results for almost no effort. The only time I properly manage my money is when I move it from my checking account into my investments; I keep an eagle eye on things once my short-term savings are converted to a long-term asset.
If one uses this method and avoids debt whenever possible, virtually everyone can build a really nice nest egg without agonizing over where all the money goes. As I said, I don't think tracking every penny is worth the effort; what you spend where doesn't matter so much as long as you manage to save some of the money at the end of the day.