Near‐constant Internet access through desktop or mobile devices has turned self‐service support forums into the first port of call for users seeking to troubleshoot product or service issues. The firms providing these products and services also benefit from this trend since it reduces user support costs by diverting service requests away from costlier support channels, such as help desks. For the continued success of such a forum, however, the managing entity must ensure that users receive timely solutions to their inquiries quickly and regularly. We develop a mathematical model of a user forum's operations to obtain a “white box” view of a user forum and reveal the support system's dynamics. Then, using a large and comprehensive dataset of questions and answers from Apple's iPhone user forum, we empirically estimate the forum's performance to validate the predictions of the mathematical model. Our results demonstrate that the predictions closely match the forum's actual performance, with an error of less than 10%. We then propose and analyze an optimal threshold policy that boosts a thread to rekindle user interest and demonstrate the benefit of our intervention policy in managing the iPhone forum.