There are a few and it all depends on the angle you want to attack the problem from. One generic formula would be the Threshold Analysis method where you pick a key metric for your product (like messages sent for Slack, files uploaded for something like Dropbox) and you try to find the minimum threshold of usage that predicts user retention.

Example: Users who send 0-2 messages: 15% retention Users who send 3-9 messages: 25% retention Users who send 10+ messages: 75% retention ← Aha threshold!

But you need to do a lot of testing/validation for this. You can: - Test different thresholds - Validate across different time periods

A simpler formula would be the Time-to-Value Framework: Aha Moment = Fastest path to meaningful outcome

In here you are searching answers for questions like - How quckly can a user get value? - What's the shortest path to success? - What obstacles slow down value realization?

Hope that helps a bit!