Yeah, I have banners all over the measurection site.
They only generate a pocket full of change... but I use them in another way to generate income.
Accept donations for your site. We do, and we call them "SOS Sponsors". We give special perks to our SOS Sponsors. They get:
- Free email address
- Access to Who's Online page
- Custom User Title
- Access to a couple of other private forums
- Access to our photo gallery.
My site has the banner ads on the top and bottom of every page... plus I have some in the sidebar.
Now here's the trick.... how I use the banners to make extra money - unrelated to the banner: The banners are annoying. I use my banner rotator mod, and the other admin even adds rather large banners in pushing the page further down. It's annoying with the top banners.
HOWEVER, my "SOS Sponsors" have the option of turning OFF the top banner in their profile. This is an advantage to being a sponsor.
Also, some don't like the sidebar, especially people on WebTV or with small monitors. SOS Sponsors can turn the sidebar off. For regular users, they can only choose left/right - thus they can't hide the ads.
So my theory, just make the ads annoying enought that they will donate for an "ad free" option.
I'm thinking of initiating a "popup" ad (once per day) that Sponsors can avoid.

I think that's the key. People don't like to pay for stuff. So don't take the angle that you are charging for access. I maintain the stand that my site is FREE. But there are some special perks only available to Supporters. Compare it to all the goodies you can get when you make a pledge to PBS.

Just my 2 cents/web philosophy.
