Mobile banking services have the potential to transform access to banking, by allowing individuals to access far away bank accounts from their mobile phones. However, adoption of these services frequently remains low, especially amongst rural populations, who have the most to gain from them but lack the knowledge or experience to use these services. In this study, we examine how best to inform and encourage use of mobile banking services, comparing individual encouragement to encouragement of adoption by a peer leader. We do this using an RCT with 400 female microfinance clients where we provide combinations of training on mobile banking with small incentives to encourage adoption of mobile banking services for the individual or for the group leader. Using both administrative data and a self-reported endline survey two months after the interventions, we find that individual incentives increase use of mobile banking services by 16 percentage points, double the control mean of 15% using mobile banking services. However, incentives for the group leader to encourage others in the microfinance group to use mobile banking services result in significantly higher use of 36 percentage points, along with increases in the value and number of mobile banking transactions. We collect detailed data on mechanisms, and find that incentives for the group leader result in large increases in knowledge about mobile banking, frequency of knowledge sharing with peers, and confidence in how to safely conduct digital transactions. Heterogeneous treatment effects reveal that women in microfinance groups where the group leader had already used mobile banking services see significantly larger treatment effects. These findings highlight the importance of thinking about influential members of a social group in encouraging technology adoption.