Any business that compels you to exploit, manipulate and/or compromise relationships with family and friends, to sell product is one to be avoided, if you care about these people and have any personal integrity.
The Kicker: If you should attend one of these types of multi-level marketing "get togethers" and the organizer takes you aside following the presentation, and asks you to sit down and write out the name of every person you know or have ever met, RUN, don't walk out of there!