If NG offered the opportunity for anyone to display their own custom linked banner in the ad box's on the top and bottom of every page, in random rotation with the current advertisements and other custom's, would anyone buy the space?
I can see it benefiting the site with it's financial situation even more so than the current donations/supporter option as well as anyone taking advantage of the opportunity because shit, NG's still pretty fucking popular right?
Don't hide the ad's, let users pay to put up their own ad's, make more money, everyone benefits.