The group of girls I do bootcamp with just started this and I honestly think it is crap. It is essentially slimfast, which does work in the sense that it makes you lose weight because you are consuming low calorie meal replacements instead of real food.
My issue with the product is that it doesn't teach you how to eat in the long run. Are you really going to drink a smoothie twice a day or the rest of your life? No, probably not. I don't like the idea of reversing the effects of my crappy processed food diet by consuming a proccessed food.
I also dont care for their marketing plan. You are correct, it is essentially a pyramid scam. You get your friends to buy, they send you free product, they get their friends to buy and you both get free product and so on.
They also have been a bit dishonest in some of their claims. They claim that their shake has less calories then leading brands, but that is when their powder is mixed with water not milk as they recomend you do if you are using it as a meal replacement. Some of the flavourings have artifical sweateners and it is just general crap.
If you are in a pinch and need something low cal, sure a shake here and there is OK but it takes the same about of time to grab a greek yogurt and a bananna.