Clarification: I would like to understand this feature better. Are you referring to the bell icon on the Facebook page, which calls to attention important stories that the user would probably be interested in, along with key reminder for events such as a birthday of a friend or an event that the user has shown interest in attending through the Facebook Events feature? Answer: yes
Assuming core objectives of this feature are to drive user engagement and to align with Facebook's core mission of bringing the world closer together. Is there any other objective that I should consider? Answer: No
Here are some key metrics that I would look at to measure the success/performance of the notifications feature:
- CTR(Click Through Ratio) of notifications - How often does the user actually click on the notification to actually see the post.
- CTR of story updates from friends vs forum activity vs post on a marketplace notifications. CTR actions on adverts can be interesting from a revenue perspective as well.
- Ratio of actual action performed after opening posts (likes, comments, shares).
- Additional connections (friendship requests) made after performing likes/comments on a shared post.
- Ratio of remove notification action performed.
- Ratio of action performed to turn off notification about a certain notification type(example: stop reminding me about birthdays).
- DAU data based on changes to daily notification and measured through A/B tests.
- User retention and churn on a weekly and monthly basis.