In a two-sided market model, we work out a profit-maximizing firm`s optimal price and calculate the social welfare level driven from the pricing. We explore some policy experiments. If a social planner makes only one side of a two-sided market perfectly competitive, which side should the social planner choose to make it competitive? We compare the social welfare under the monopolist`s pricing with the social welfare level for a case in which only one side becomes perfectly competitive. We check whether making only one side competitive improves social welfare.