The authors develop and evaluate an online networking intervention, Building Relationships and Improving Opportunities (BRIO), built in conjunction with the networking literature and social cognitive theory (Bandura, 1986, 1999). A field experiment using 491 unemployed job seekers shows that the intervention increases networking intensity, networking self‐efficacy, and proximal networking benefits. Further, the intervention generates higher quality reemployment through its positive effects on networking self‐efficacy. Individuals who completed the intervention and were also lower in extraversion showed the most positive improvements in networking self‐efficacy and reemployment quality. The study advances the literature by uncovering the mechanisms through which a networking intervention may result in improved reemployment success, and demonstrating the moderating role of individual differences in affecting intervention outcomes. The study helps practice by providing a publicly available, research‐based training to improve job search networking.