Decay
How quickly a post’s engagement falls off after publishing — the half-life that separates evergreen content from a one-day spike.
How INFLU measures it
Measured as engagement over time since posting; slow decay on Reels and carousels signals the algorithm keeps redistributing the post.
Live example — Footwear
#1 @tiempos.running
TIEMPOS
score 79.3 · Established
Current Footwear rankings → Footwear leaderboard
Related terms
Momentum phase
The direction-of-travel label for a creator — whether their recent performance is accelerating, holding steady or cooling relative to their own history.
Watch time
Cumulative seconds viewers spent on a video — the ranking input Instagram’s recommendation system optimises hardest for.
Reels
Instagram’s short-video format and its primary discovery surface — the only format that routinely reaches large non-follower audiences.