We experimentally investigate two relevant drivers of payments in voluntary settings: the effects of audience and peers. Our 2×2 between-subjects design varies the interpersonal closeness of buyers (Strangers vs. Peers) and the observability of their payments to other buyers (Anonymous vs. Public). This allows us to enrich the research on both drivers and identify whether payment observability (audience effect), the presence of known others (peer effect), or the combination of both affects voluntary payments. Payments are, on average, higher if they are made public and if buyers feel close to each other. While the effect of audience and peers on payments is additive in total, we do not find an interaction effect, if payments are observed by peers.