Consider a product that has network effects in the following sense. Consumers are named using real numbers between 0 and 1; the reservation price (i.e., willingness to pay) for consumer x when a fraction z of the population uses the product is given by the formula r(x) f (z), where r(x) = 1 - x and f (z) = z. What is the reservation price for consumer x when a fraction z of the population uses the product?