The share of users from a given cohort who keep using the product after a set window, usually checked at day 1, day 7, day 30, and beyond.
Netflix's 2023 shareholder letter showed an annual retention rate above 90% across its 260-million-subscriber base, a number unusual even among entertainment subscriptions. The company attributed the strength to original content investment and the post-2022 crackdown on password sharing, which converted freeloaders into paid accounts rather than driving them away.