The simplest valuation method that's been described recently is the peer group valuation. YGYI is trading at a discount to their peers.
If Youngevity were trading in-line with their peer group the stock would be valued at 51-54 cents per share based on 2015 projected revenue of 171 million dollars.
From what I am able to understand, the market is unsure if recent acquisitions will have the required organic growth to get them there.