Playbook: Lazy-load ads without nuking viewability

Playbook: Lazy-load ads without nuking viewability
What it does: defers ad requests until units near the viewport, so impressions count and RPM holds.

Setup (effort 2/5):
— Set GPT enableLazyLoad({ fetchMarginPercent: 200, renderMarginPercent: 100 }) — fetch 2 screens out, render 1.
— Mobile: drop fetchMargin to 120, render 60. Tighter, less wasted fill.
— Exclude the above-the-fold leaderboard. Lazy-loading it just delays your highest-RPM slot.
— Watch viewability in GAM after 48h. Below 60%? Margins too tight.

RPM lift seen: +8-14% from fewer dead impressions, better viewable rate.

Pros: cleaner fill, faster LCP. Cons: over-tighten and you starve fill; under-tighten and you gain nothing.

Lift: ★★★★☆ — Risk: ★★☆☆☆
Best for: long-scroll sites with 6+ in-content slots. Skip if your pages are short — overhead isn't worth it.