What are sticky ads?
A sticky ad stays fixed in a set position on screen while the user scrolls the rest of the page — most commonly a slim bar anchored to the bottom of the viewport, or a unit pinned in a sidebar rail. Because it remains visible instead of scrolling out of view, it accumulates far more viewable time than a standard in-content banner — and viewability is one of the strongest drivers of ad value.
Sticky ads are sometimes called anchor ads (the bottom-pinned bar) or sticky sidebar / sticky rail units (the desktop side placement).
Why they earn well
The value comes down to attention and viewability:
- They stay in view. A standard banner might be seen for a second before it scrolls away; a sticky unit is visible for much of the session, driving high viewable-impression rates.
- High viewability lifts demand. Advertisers pay more for inventory they know will actually be seen, so sticky units tend to command strong eCPMs.
- They don’t cost extra content space. A bottom anchor overlays the page rather than pushing content down, so you add a high-value slot without redesigning the layout.
The rules that keep them safe
Sticky ads walk a line: visible enough to earn, unobtrusive enough not to annoy or trip policy. Keep them safe by following a few constraints:
- Respect size limits. Google’s policies cap how much of the screen an anchor/overlay ad may occupy (a slim bar, not a half-screen block). Oversized stickies risk both user complaints and policy action.
- Always provide a clear close control. Users must be able to dismiss a sticky unit easily. Hidden or fake close buttons are a fast route to trouble.
- One at a time. A bottom anchor and a sticky rail and an interstitial stacking up is a bad experience — pick placements deliberately.
- Mind mobile. On small screens a sticky bar eats scarce space; make sure it doesn’t cover navigation or core content.
- Protect Core Web Vitals. A poorly implemented sticky unit can cause layout shift. Reserve its space and load it cleanly. See Core Web Vitals & ad monetization.
Sticky vs interstitial
Both are high-value formats, but they trade off differently:
- Sticky is persistent but small — always visible, low interruption. Safe to run continuously.
- Interstitial is occasional but full-screen — very high CPM, but intrusive and tightly policy-governed, so it must be frequency-capped and placed only at natural breaks.
Many publishers run both: a sticky anchor for steady, high-viewability earnings and interstitials sparingly at transitions.
The bottom line
Sticky ads are one of the best risk-adjusted formats a publisher can run: high viewability and strong CPMs, with modest UX cost if they’re kept slim, dismissible, and singular. Treat them as a permanent, well-behaved slot — not an excuse to pin as much ad as the screen allows — and they’re a reliable contributor to yield.
To get the most from sticky inventory, route it through competitive demand and tune it as part of ongoing yield optimization rather than setting it once and forgetting it.