Dear Philippe Dufresne,
It's a pleasure to answer you and I'm going to do it in globish.
The first point explaining the succes and the appeal of your method for me is to reduce the ambition in a first time. Then you propose for example to memorize 1500 words. It's possible for anyone. If you have to memorize 5000 words, you courage is immediately falling down. With this modest aim, you'll think you are able to do it and you'll try. And with this method you'll note soon that's actually easy .
At this step two helps are done: the sound, because of these series of sounds allow to drill the vocabulary many times, and this excellent explanation about use of sh'wa. With the sh'wa, learning vocabulary is easer and better, near the reality. You are suddenly learning the same words, the same sounds, which you can catch when you are watching the TV or hearing a conversation.
The second point is certainly, for me, the sentence building and the way to show in each "etape", for instance, the use of tense, with sentences you can repeat ten times or more, like a perfect model in your mind. I'd never understood and felt this important step for learning a language.
In fact and to conclude, I think the method is interesting with all its means got together, their addition and the real difference comparing several methods is maybe its particular spirit. Anyway, the method has been working very weel for me and I'm feeling like going on with it to improve my globish.
Congratulations on your work. Best regard.