A return is a job done twice, not an open

Many event dictionaries call any session a return. That makes notification experiments look like loyalty. In a study we prefer a job: a completed order, a saved article that was actually read, a ride that was not cancelled. The first week then becomes a question of whether the app allowed that job twice.

Product teams sometimes resist this because the stricter definition makes the table look worse. It should. A person who opens the app, sees a paywall, and leaves has not returned in any sense that operations can staff for.

Write the definition in a sentence at kickoff. If the sentence needs a paragraph of exceptions, the event names are probably doing two jobs at once. That is a tracking problem, and we will say so rather than invent a blended rate that pleases everyone and describes no one.