This article was originally published on Jo4 Blog .

We built a suite of free developer tools: JSON formatter, JWT decoder, QR generator, UTM builder, and about a dozen others.

Then we added AdSense to every page.

Then we removed it from most of them.

Here's why.

The Original Plan

The logic seemed sound:

Free tools bring traffic (SEO)

Traffic sees ads

Ads generate revenue

Revenue funds development

We added a simple <AdSlot /> component to our UtilityPageLayout :

// Before: Ad on every utility page export function UtilityPageLayout ({ children }) { return ( < main > < AdSlot position = "top" /> { children } < AdSlot position = "bottom" /> </ main > ); }

Enter fullscreen mode

Exit fullscreen mode

Every tool page now had ads at the top and bottom.

What Actually Happened

Week 1: Impressions up, RPM decent.

Week 2: Noticed something odd in analytics.

Users on utility pages had:

Higher bounce rate (+15%)

Lower time on site (-20%)

Fewer conversions to signup (-25%)

The ads were working as ads.…