CONCEPT Cited by 1 source

Notification fatigue

Definition

Notification fatigue is the cumulative degradation of a user's responsiveness to messages when exposed to excessive or poorly-timed notifications over time. It manifests as declining open/click rates, increased opt-out/unsubscribe actions, and ultimately reduced platform engagement.

Key properties: - Cumulative: A single extra message has negligible marginal cost, but sustained over-messaging compounds into measurable harm. - Sparse negative signal: Explicit negative feedback (unsubscribes, complaints) is extremely rare relative to total sends, making it hard for short-horizon models to detect. - Long time-horizon: Effects surface over weeks, not minutes — invisible to single-message causal models.

Netflix found that without an explicit universal message cost term in the utility function, predicted "cost" of incremental messages appears negligible, causing optimization to degenerate into "always send" policies.

Seen in

• sources/2026-06-19-netflix-thinking-fast-slow-for-a-personalized-notification-system — Netflix introduced a universal message cost to keep the reward function concave and prevent degenerate high-frequency policies. Their Slow Policy explicitly manages fatigue risk at a weekly horizon.