In his commentary, O'Keefe raises some interesting questions about the meaning of effect sizes in meta-analyses of experiments, focusing on our recent meta-analysis on vaping prevention messages. In this commentary, we respond to O'Keefe's comments and make several points. First, it is not uncommon to include experiments with different control conditions in a meta-analysis. Second, the set of studies in our meta-analysis were relatively homogenous, all being experiments testing messages to discourage vaping among adolescents and young adults. Third, the control conditions in each of the studies in the meta-analysis were appropriate for each given study, and our results show homogenous effects on most outcomes. Fourth, our meta-analysis finds meaningful effects that are timely and will be useful to researchers and practitioners alike. As this literature continues to grow, so too will knowledge about the effects of vaping prevention messages and moderators of those effects.