I suppose it depends how active that 3% of the userbase is.
If those 3% of users are responsible for e.g. 20% of the page views, and therefore potentially 20% of ad placements, maybe they are really having a big impact?
Isn't most of the income (or all?) for reddit from ads and awards? So the people actively adding value/content gets punished, while the amount of people seeing ads remain the same? Seems even more crazy if true then.
If those 3% of users are responsible for e.g. 20% of the page views, and therefore potentially 20% of ad placements, maybe they are really having a big impact?