Why has the decision to invite foreign election observers become an international norm? More generally, how do international norms develop in the absence of incentives for cooperation or activism by norm entrepreneurs? Motivated by the case of election observation, I argue that international norms can be generated through a diffusely motivated signaling process. Responding to increased benefits associated with being democratic, international election observation was initiated by democratizing governments as a signal of a government's commitment to democracy. Increased democracy-contingent benefits gave other “true-democrats” the incentive to invite observers, resulting in a widespread belief that all true-democrats invite election monitors. Consequently, not inviting observers became an unambiguous signal that a government was not democratizing, giving even pseudo-democrats reason to invite observers and risk a negative report. I evaluate this theory with an original global dataset on elections and election observation, 1960–2006.