Amway Link
Here's a link to give your friend. It's very critical (sour grapes?) but there are links to other mainstream articles in there. There is a lot of information.
I was in Amway in the mid 80's. It is definitely not for everyone. There is very little left of the people that were above me and they were "successful" at the time. Luckily, my wife and I were poor and couldn't afford to shove a bunch of money into it so we didn't lose much when we stopped.