I've been doing MLM for about 25 years, but it had never become more than a resource sink, until recently. It's very easy to spend your money on tools, or leads or products, or to spend countless hours (really your MOST VALUABLE ASSET) and go nowhere.
It certainly is NOT get rich quick, even for the super stars, who tend to have bursts, then lulls of growth. It is, certainly, about hard work, and a good (healthy) work ethic.
I think the secret is NOT about companies OR products, but about PEOPLE.
Building a spider-web of real contacts is the key, and, the current explosion in social networking, and how traditional marketers are trying to target it is just one piece of evidence.
Having part of your spider-web contain a mastermind mentoring group, where you can balance your primary personality against others, complimenting your effectiveness is crucial.
Download Michael Dlouhy's (my mentor and very successful MLM'er) FREE ebook, that discusses MLM in general from here http://tkoker.successin10steps.com, and the 10 hours of additional training that is made available for FREE (audio, live phone calls, eBooks, too), I can provide (all free, no strings at all), if you're interested.
This is really free, no spam, no hidden agenda, no companies or products, just heart-felt mentoring.