My parents finally ended a 9 year run with Amway/Quixtar this year. It effectively bankrupted them, almost destroyed their marriage (I was my Mom's fault because she wasn't "trying" hard enough to "make it"), and left them with a basement full of crap. I tried to get them to "see the light" about the "business" but to no avail. Thankfully, it didn't ruin my relationship with my Dad... a lot of family members in other cases who don't go along aren't so lucky.
As a side note, in addition to the veiled ponzi scheme that is Amway/Quixtar, an even bigger fraud is being carried out by the big cheese distributors who don't tell their underlings that most of their income comes not from the AmQuix business but all of the meeting tickets, convention tickets, book, and tapes that they sell them.