Overall I get about 3 to 4 notifications from Facebook per day, so the quantity isn't too high. It also helps me avoid the habit of frequently loading Facebook to check for new notifications when there usually aren't any.

Thanks for the perspective, checking for notifications could be even more of a distraction in some cases!

I have a few users on https://movinggauteng.co.za using web notifications for transit updates. I'm intentionally not sending many for now, because I'm still working on a way for commuters to choose when to get updates.

This seems like a great use of notifications unlike so many apps where they exist mainly to promote compulsively habitual usage.