Why view-velocity matters more than view-volume
The FYP ranker reads view-velocity (views per minute, normalized to current distribution wave) before it reads cumulative view-count. A video with 10,000 views accumulated over 6 hours and one with 10,000 views accumulated in 30 minutes generate different ranker reads — the second shape unlocks the next probe wave because it indicates above-baseline-for-cohort velocity; the first shape doesn't move the gate.
