Google primarily considers a site "ad-heavy" based on two major factors: intrusive ad experiences (which ruin the user's flow) and excessive resource usage (which slows the device).
1. Intrusive Ad Experiences
This criteria is based on the Better Ads Standards, which identify ad formats most annoying to users. Sites with these experiences may have their ads filtered by Google Chrome. Key intrusive examples include:
Pop-up Ads: These appear abruptly and cover content.
Prestitial Ads with Countdown: These are full-screen ads that appear before the content loads and force the user to wait before continuing.
Large Sticky Ads: Ads that remain fixed in place (like a banner at the bottom) as the user scrolls, taking up a significant portion of the screen.
Autoplaying Video Ads with Sound: Videos that start playing automatically and include audio.
Specifically on Mobile:
A site is considered ad-heavy if the Ad Density is Higher Than 30%. This means the ads take up more than 30% of the vertical space on the screen.
2. Excessive Resource Usage ("Heavy Ads")
Google Chrome also monitors and blocks individual ads that drain the user's resources. An ad is flagged as "heavy" and removed if it exceeds certain technical limits, even if the user hasn't interacted with it. These limits include:
Bandwidth: Using more than 4 MB of network data.
CPU Time: Consuming more than 15 seconds of CPU time within a 30-second period, or more than 60 seconds of total CPU time.
3. Page Layout
Google's older, but still relevant, Page Layout algorithm looks at sites where too much advertising is placed "above the fold" the area a user sees immediately without scrolling. If ads push the main, original content down so that it's difficult for the user to find right away, Google may view this as a negative user experience.