The goal of every open source project is to gain as many satisfied users as possible. To this end, open source software producers should focus on both product development and communication. Currently, most open source projects are mainly concerned with developing code using the most appealing technologies and introducing fancy features. On the contrary, open source software producers seem to lack good communication strategies. In this paper we describe the communication strategies adopted by three successful companies that are active in open source software development. The goal of the paper is to provide some hints that could help other open source software producers identify communication strategies that are effective in promoting their products on the market.