When a majority of your customers are being unknowingly screwed over as you reap a huge amount of unnecessary producer surplus, it's a losing proposition in the end. Companies like Herbalife can just do it on a scale where it takes a long time to fizzle out.
Management Quality: If you read the really long presentation linked to in the article, they seem competent, but sketchy.
Retained Earnings: I have no idea.
Competition: Direct selling shitty looking health shakes? The seem to be reasonably well established.
History: It's been applying the same trick all along. Not much to go on here.
Input Costs: Well under control. Good.
Market Differences: They seem to be quite good at entering into different markets, so this goes well for them. It might be interesting if they could diversify their product lines.
Product Quality: Problem here, as I don't see what distinguishes them other than sales talent.
Quick PEST analysis:
Polictical: Problem. It's could be described as a pyramid scheme.
Economic: Economy seems to be picking up, and it does not strike me as a good that swings too much with the economy. However, they could have problems recruiting sales staff in a better economy.
Social: Health food is a trend that I think will continue.
Technological: Not really an issue.