The site that doubled ad density and revenue stayed flat

The site that doubled ad density and revenue stayed flat

The claim: an owner cranked Mediavine's density to maximum, expected +40%, got +3%. "Density doesn't matter."

The asterisk: revenue per session barely moved because viewability and fill have ceilings. Stacking three more units below the fold added impressions that mostly went unseen, so eCPM on those slots was a rounding error.

🚩 Hidden variable: the metric that moved was pageviews per session — down 6%. Heavier pages pushed Core Web Vitals into the red, bounce crept up, and the extra ad slots ate the sessions that would have seen them.

The revenue line was flat because two effects canceled.

Not saying high density is bad — saying "density up, revenue flat" is a net of two forces, and reading it as "no effect" misses both.