“If you haven't registered an account it's very unlikely that you're going to pay for a subscription... if you don't have their email you can't win them back if they don't sign up you can't do so many of the other parts of value delivery and value capture.”

Account registration is your last chance to build a durable relationship with every install

Sign-up / account registration rate is Carter's first upstream proxy metric in the Subscription Value Loop — not because it directly drives revenue, but because without an account you lose the email, the push channel, and all re-engagement ability. Benchmarked from survey data across 600 apps, it signals the maximum fraction of installs that can ever convert to paid.