Notification systems are usually built as a delivery mechanism and then filled by whoever wants something delivered.

A test before sending

Would this be worth interrupting the person for, if you had to do it in person? Almost nothing marketing sends passes, and a surprising amount of product messaging does not either.

• Batch anything that is not time-critical. Three notifications an hour apart are three interruptions; one digest is one.
• Let people turn off categories rather than everything. An all-or-nothing switch means the answer becomes nothing, and then you have lost the channel for the message that mattered.
• Never use a badge for something that is not actionable. A red dot that means "we published a blog post" teaches people to ignore red dots.

That last effect is permanent and applies to your important notifications too. Spending the badge on marketing is borrowing against the one you will need for a failed payment.