We study the use of word-of-mouth marketing strategies on social networks to maximize profit from the sale of a new product.The key feature of this problem is how to choose the original customers to help promote the product and which price should the product be cost.On account of the diverse accepted price of each person and the influence of purchase decision between neighbors in a social network, the spreading process is dynamic.Thus we simulate the process with stochastic parameters and offer some suggestions on choosing nodes and optimal pricing.