Google has announced a new AdSense ad format named side rail ads. Side rail ads stick to the sides of your web pages when the user viewing the page is on a widescreen device, such as a desktop computer.
Google wrote, "Today, we're announcing a new ad format called side rails. Side rails are ads that stick to the sides of your pages when they're viewed on widescreen devices, such as desktops."
Those who have already tuned on anchor ads will see the side rails automatically start to show up on your site after December 13, 2022, Google said.
Don't want side rail ads? Then you can turn off this option in your Auto ads settings within the AdSense console:
Forum discussion at Twitter.
