This is a bad way to think. Many of the costs of running a business are per-user, so revenue must also be measured per-user. As users join the per-user revenue

This is a bad way to think. Many of the costs of running a business are per-user, so revenue must also be measured per-user. As users join the per-user revenue stays the same (to first order) but as apps join the revenue-per-user-per-app tends to drop.