When I was working with people who were coming out of cults, it also opened my eyes to all the other types of "cultic" groups out there that use some form of deception (hyping up the money you may make) and control (getting you so emotionally involved you can't see the business objectively), and found that there are many, many claims against Amway and other types of multi-level or so called networking schemes.

Here is a good basic page on multi-level or network marketing and what is wrong with it.
What's Wrong With Multi-Level Marketing?