A specific in-product action you have measured to be the strongest predictor of long-term retention , so the entire onboarding flow gets reorganized to push every new user toward it.
Josh Elman's growth team at Twitter in the early 2010s found that users who followed at least 30 accounts in their first session were dramatically more likely to be active a month later. The signup flow was redesigned to push contact import and suggested follows aggressively, on the bet that hitting that single number was worth a worse first impression.