They come and go so quickly. I remember the good old days with linkexchange.com. Are banner exchanges dead? Would it be worth starting one?
Banner exchanges seem to get a much lower click through rate than text ad exchanges. I would start a text ad exchange before a banner ad exchange.
My personal opinion is that all banners have lost their value. I get about a .001 on some of my cpa banners. People actually ignore them these days. Text links are a lot better if it is in context.
Good text ads with strong descriptions can certainly generate decent click rates but banners can still be very productive in the right environment. For example on many adult tubes, a 300 banner can generate many clicks as they are often displayed to look like a thumb image. I think their is still some value in banner exchanges. They tend to be used by lots of newer webmasters.
it might be a good idea if you start a niche banner exchange. It would make all the banners way more relevant. Plus it would give the webmasters a higher ctr.