Viewability padding (rootMargin) vs making the unit sticky

Viewability padding (rootMargin) vs making the unit sticky

What it does — both raise measured viewability, which raises eCPM. rootMargin requests the ad early so it's loaded by the time it scrolls in; sticky keeps it on screen longer once seen.

Setup effort (1-5) — rootMargin: 2 (one observer param). Sticky: 3 (collision handling).

RPM lift seen — rootMargin tuning alone: +4-8% via fewer 'never seen' impressions. Sticky: +10-18% because dwell-in-view skyrockets and buyers pay for that.

Pros / Cons —
rootMargin: invisible to users, no UX cost, but ceiling is lower, it only fixes timing.
Sticky: huge viewability gain, but real UX/CLS cost and Better Ads density risk if overused.

Verdict — Do rootMargin first, it's free viewability with zero downside, then add sticky selectively to your highest-value unit only. Don't make three units sticky chasing the same metric.

Lift: ★★★★☆ — Risk: ★★☆☆☆
Best for: every site (rootMargin) and high-value desktop slots (sticky). Skip multi-sticky stacks.