People's decisions are influenced by the decision environment. In fact, no choice is made in a vacuum, as there is no neutral way to present choices. Presenting choices in certain ways — even if this happens unintendedly — can thus "nudge" people and change their behavior in predictable ways. "Nudging" is a concept from behavioral economics that describes how relatively minor changes to decision environments (e.g., setting defaults) influence decision outcomes — which often remain unnoticed by the decision maker. We extend the nudging concept to the digital environment. We define "digital nudging" as the use of user-interface design elements to guide people's behavior in digital choice environments. We propose a digital-nudging process and identify opportunities for future research