In a field experiment, we examined whether conveying descriptive social norms (e.g., "this is what most people do") increases charitable giving. Additionally, we examined whether people are more likely to conform to the local norms of one's immediate environment than to more global norms extending beyond one's local environment. University students received a charity organization's information brochure and were asked for a monetary contribution. An experimentaldescriptive norm manipulation was embedded in the brochure. We found that providing people with descriptive norms increased charitable giving substantially compared with industry standard altruistic appeals (control condition). Moreover, conveying local norms were more effective in increasing charitable givingthan conveying global norms. Practical implications for charity organizations and marketing are proposed.