Anchor Ads

Anchor ads (also called sticky footer/header ads) are fixed-position ad units attached to the edge of the browser viewport, typically the bottom of the screen on mobile. They stay visible as the user scrolls, giving them high viewability rates (often 80-90%).

The trade-off is user experience — anchor ads consume screen real estate and can feel intrusive. Most ad networks offer anchor ads as an optional format. Google's own guidelines recommend keeping anchor ads small (320x50 on mobile) and ensuring they have a visible close button. Overusing anchor ads can increase bounce rates and hurt your site's overall engagement metrics.