How can a community of practice help further the practical application of cancer control research? In 2011, the National Cancer Institute (NCI) launched an online community of practice, Research to Reality (R2R). R2R aims to infuse evidence-based strategies into communities by engaging researchers and practitioners in a joint approach to research dissemination. To measure community growth and engagement, NCI measures data across 3 program domains: content, interaction, and activity. NCI uses Web analytics, usability testing, and content analyses to manage and evaluate R2R. As of December 2013, R2R had more than 1,700 registered members. More than 500 researchers and practitioners register for the monthly cyber-seminars, and 40% return each month. R2R hosts more than 15,500 page views and 5,000 site visits in an average month. This article describes the process of convening this online community and quantifies our experiences to date.