I am not typically cynical, but I just did a quick search on Market America, and have to say I'm very wary of businesses that use these terms: "Business Opportunity", "Residual Income" & "MLM" (Multi Level Marketing). What makes me even more wary is when I see the phrase "we are NOT an MLM". That almost guarantees that they are.
I know there are lots of opinions on this board, and all kinds of people might jump on and defend MLM and talk about their successes. Power to them. But I've tried that a few times years ago, and learned early on it was NOT for me. To me, I might as well join a cult. Having said that, I know nothing about Market America specifically, but good luck if it interests you.