Where the term comes from
The phrase comes from product and growth teams in the early 2010s, popularised by people like Sean Ellis (Dropbox) and Chamath Palihapitiya (Facebook). The textbook examples are Facebook's "add 7 friends in 10 days", Slack's "2,000 messages sent within a workspace", and Dropbox's "one file in one folder on one device".
How it differs from signup
Signup just means someone finished the form. The aha-moment is deeper. For DTC ecommerce it is usually the first purchase. For self-serve SaaS it is often the first export, first publish, or first teammate invited. For B2B SaaS it tends to be the first real product action by two or more people in the buying account within 14 days, because a single user rarely predicts whether the whole account stays.
What to do with it
Use the aha-moment activation calculator to test a candidate event against your own retention split. The aha-moment for DTC post covers the DTC-specific patterns, and time-to-value in ecommerce looks at how quickly activation should happen.
Last updated May 31, 2026.