Scroll-depth ad injection vs fixed-paragraph injection

Scroll-depth ad injection vs fixed-paragraph injection

What it does — both place in-content ads, but trigger differently. Fixed-paragraph injects at paragraph N regardless of length; scroll-depth injects based on how far the reader actually gets (25/50/75%).

Setup effort (1-5) — Fixed-paragraph: 2. Scroll-depth: 4 (scroll tracking + dynamic insertion).

RPM lift seen — Fixed wastes inventory on long articles (ads cluster at the top). Scroll-depth spreads units to where readers are, lifting viewability and +8-14% RPM on long-form vs fixed.

Pros / Cons —
Scroll-depth: ads land where eyeballs are, better viewability, fewer wasted requests, but complex and can cause late-shift CLS if not reserved.
Fixed: predictable, simple, but over-loads short pages and under-loads long ones.

Verdict — Use fixed-paragraph as your baseline; switch to scroll-depth only on content over ~2000 words where the spread matters. Reserve height either way.

Lift: ★★★☆☆ — Risk: ★★★☆☆
Best for: long-form publishers. Skip scroll-depth on uniform short posts, the complexity won't pay back.