I don't pretend to know very much about Network Marketing/MLM's but I have run across a Very Good Conversation over at the Work at Home Forum.
Basically, the concept is having a Product that will Sell, the Advertising Behind the product, and a Company that backs up the product with Support and Customer Service.
The Product could be anything, Weight Loss, Software, Cell Phones, New Inventions, the list goes on and on. If you have the right product, you will be able to find a Downline (people who follow you into the venture).
If you have thought about joining or starting an MLM, I would suggest you at least evesdrop on this conversation. You can even join in since it is in a Forum setting. If you were on the new Home Page and got transferred here through a link in an article, Please Click Here to Return to Working at Home on the Internet (the New and Improved Version). For your convience: E-Mail Questions Good Luck in YOUR Endeavors