No economist could remain unmoved by the brouhaha that has engulfed Herbalife, the nutritional supplements company. The sponsors of football teams such as Barcelona and LA Galaxy, it sells diet drinks and protein bars through a network of small distributors, many of whom recruit, train and supply further distributors. This may be an intelligent way of selling the product through word-of-mouth. But doubters wonder whether Herbalife isn't too reliant on distributors filling their spare bedrooms with protein shakes, which they hope to sell at a profit by recruiting yet more distributors.