In this article we use the results of a field experiment to investigate whether the choice to convert to permanent vote-by-mail (PVBM) status is driven primarily by individual voters' characteristics—such as a registrant's propensity to vote—or the messages elections administrators and advocates use to convince them to change their status. We find two significant outcomes. First, regardless of the message received, high-propensity voters are much more likely to convert than are low-propensity voters. Second, among low-propensity voters the convenience-based message was the least likely to cause conversion to PVBM status, and none of the messages had a significant effect among high-propensity and prior-PVBM registrants. Taken together, these results suggest that the current focus by scholars and practitioners on VBM's impact on the costs of voting may be misplaced.