On one end you have video games. Games get played every day. On the other end you apps that help you file your taxes. You only need to file your taxes once a year.

How often you're meant to use a product comes down to the natural occurrence of the problem your product solves.

The natural frequency of the problem you solve acts as an in-built notification system for your app. If you do a good job of solving the problem once, the next time it comes up people will think of you. Help them solve it again and you begin to cement this relationship into a habit.

If the problem comes up less than once a month then this all starts to break down. People forget about you by the time the problem comes around. It's much harder to build a habit around your product if the problem only happens every few months.

If you're primary use case deals with an infrequent problem then this is an excellent reason to think about layering in a new, more frequent use case.

Taxes once a year, what about helping people track expenses month to month? Holidays once a year, what about local experiences people can do on the weekends?