Of course you could lose 30 pounds in 90 days this way too, I was just giving an example
The point is that the process is deterministic. You know exactly (give or take a day or two) when the goal will be reached.
This is just a simple form of weight control, a linear equation basically. It's compatible with healthy (you don't have to binge just because you can) or unhealthy food habits. It's not concerned with
what you eat!
The advantages that I see (and why it worked for me):
1. It's not constant deprivation like almost all other methods. You can have your eating days (and binge if you really want to) but still be on target long-term. Just be ready to compensate later for any excesses.
2. It's so simple. You don't have to count calories, avoid certain foods, bla bla bla. Eat what you like. Eat healthy if you want to (so much the better), but it's not strictly necessary just to lose the weight.
3. It's flexible. I gave some tips in my first post on how to mix it up a bit. There are many more.
And it doesn't preclude a healthy diet. You can combine it with a healthy diet, and maybe you won't have to do any fasting days at all, since you lose the weight naturally anyway.