The HIV epidemic has been the most significant public health crisis of the last 2 decades. Although Experimental Social Innovation and Dissemination (ESID) principles have been used by many HIV prevention researchers, the clearest application is the series of model-building and replication experiments conducted by Kelly and colleagues. The model mobilized, trained, and engaged key opinion leaders to serve as behavior change and safe-sex endorsers in their social networks. This paper illustrates how ESID principles were used to develop, test, and disseminate an innovative social model and discusses the challenges of applying ESID methodology in the midst of a public health emergency.