In this dissertation, I study how consumers influence each other in the adoption and engagement of digital goods. In the first essay, I study peer influence in mobile game adoption. Although peer effects are expected to influence consumer decisions, they are difficult to identify in observational studies due selection bias: Friends share common characteristics and behave in similar ways even without peer effects. I use a novel approach to estimate unobserved characteristics which endogenously drive tie formation and use the estimates to control for selection, without need for instruments. This is the first paper to use latent space to reduce bias in peer influence estimates. I find that peers account for 27% of mobile game adoptions, and th...