Myth: stuffing the first comment with keywords boosts reach

Myth: stuffing the first comment with keywords boosts reach
No reach signal from comment keywords. n=180 accounts, A/B 4-week window.

— Keyword-stuffed first comment: reach delta +0.4% (noise)
— Caption-front keyword (first 125 chars): +3.9% reach
— SEO alt-text filled: +2.1% on image posts

Ranking reads the caption and on-screen text, not a hidden comment dump. So what: move your keywords into the first line of the caption and the alt-text fields. The 'secret comment' trick tests as a placebo.