I find that MLM (multi level marketing) companies can be an easy way to strain friendships -- uncomfortable product parties, and 'casual' sales pitches. People get extremely involved into it because they have so much vested, both time and money wise, that they become personally insulted once someone bashes the company they sell for or does not want to buy their product. I have heard this line one too many times: "but why make the large corporations rich when you can buy from me?"
Quixtar is the same way.