That being the case the only way to increase revenues is to increase membership. I would guess that you can count on x% of members to donate y amount of money even though the donors are a very small percentage of users. So you have to increase the users.
How? Go back to the old free wheeling FR where true believers from every nook and cranny of the right, center and occasional liberal got to tee off on each others views without fear of getting shown the door or harpies calling moderators because some poster isn't toeing some line.
Keep it clean but move it back to the free wheeling FR where the wars between libertarians, socons, Econs, believers and non believers were epic, so to speak.
That is where the donation money is, among those who are true believers in whatever it is they believe and are guaranteed an ad free site where their views can be aired without fear of "zotting" if they play by the rules.
+1
This! Especially the part about the harpies! This is the FR I joined eleven years ago.