"Almost everyone is being sold to a ticket on a flight that has already left," said Jon Taylor, a former distributor and well-known critic of Nu Skin and other MLM companies. "It is only an opportunity for the first ones in and the ones at the top of the pyramid. If you come in late, there is no chance to get anywhere."

Around 100 students crammed into Tran's sales pitch in a room at the company's headquarters in Ho Chi Minh city. The economics students, from a prestigious university in the city, had been invited by their teacher who was friends with a relative of Tran.

Comparing Nu Skin's success to that of Facebook and the iPhone, his pace never dropped in the one- hour presentation. "Who wants to be financially free, "he asked. "I'm going to share with you something that will change your life."

After the meeting ended around 10 students approached one of his assistants for more information. Others were more skeptical. "He transmitted his enthusiasm to me," said Tran Ngoc Kim Hoang. "Do I believe him? It's 50-50."

His presentation to the students focused mostly on the financial rewards they could achieve with Nu Skin and the brilliance of the product, but he said earlier in an interview that "I tell people the whole story, which is that it's not going to be easy."

Tran, who was coy about his age but appeared to be in his late 20s or early 30s, was perhaps surprisingly honest about the bad reputation the MLM has in some quarters: "Everywhere in the world, it has a negative stigma." Asked why, he said because "so many who participate fail."

In the 1990s, Nu Skin reached settlements with five states in the United States that had accused it of deceptive marketing and overstating the income earned by distributors. In 1994, the Federal Trade Commission investigated some of the claims it was making for the efficacy of a hair loss prevention potion, an anti-wrinkle cream and a product for treating minor burns. The company paid $1 million. In 1997, the FTC fined it $1. 5 million for making unsubstantiated claims about fat-loss products.

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