Link Rot is natural. Websites change. But if you rely on ad revenue, broken links aren't just an annoyance—they are a direct leak in your wallet.
1. The AdSense Connection
When a user clicks a link and hits a 404 error page, they almost always hit the "Back" button immediately. This is a 100% Bounce Rate. AdSense sees this behavior. If your site sends users to dead ends, your "Quality Score" drops, and your RPM (Revenue Per Mille) decreases.
Wasted Impressions: You also lose the opportunity to show ads on that page. A functional page is inventory. A broken page is empty shelf space.
How to Detect Rot
You can't check every link manually. Use a "Broken Link Checker" tool (there are many free Chrome extensions) or a crawler like Screaming Frog. Scan your site once a month.
2. Treatment Plan
When you find a broken link, don't just leave it. Set up a 301 Redirect to the most relevant live page. This preserves the "Link Equity" (SEO juice) and keeps the user on your site—where they can see your ads and convert.