Sourcefire balances its own contributions and the contributions of its users very well. Because the firm plays in a market that requires continual product additions (new detection rules), Sourcefire constantly interacts with both corporate users and community contributors. By contributing code and maintaining the quality of its commercial offering, it meets the needs of the entire user base. As one of the earlier success stories commercializing open source, with more than 100,000 registered users, Sourcefire provides a great example of viral marketing and commercialization timing.