Case: lazy-rendering a sticky sidebar unit

Case: lazy-rendering a sticky sidebar unit

What it did: the desktop sticky sidebar ad didn't request until the user scrolled 25% down, then it stuck. Before, it loaded at page-top and often scrolled past unseen.

— Setup effort: 2/5 (scroll trigger + sticky CSS)
— RPM lift seen: that slot went from $2.40 to $3.90 RPM (+62.5%), page RPM +9%
— Viewability on the slot: 49% → 81%

Pros: the same slot, same size, just timed right — pure viewability arbitrage.
Cons: on short articles users may never hit 25%, so the slot underdelivers; we lowered the trigger to 15% on short templates.

Lift: ★★★★☆ — Risk: ★★☆☆☆
Verdict: time your sticky to scroll intent, not page load. Best for: desktop content with a fixed sidebar. Skip on mobile.