At the risk of irritating you and losing some much-needed business I need to do with you, I just HAVE to say this... you need serious work on how you sell your advertising space. It is a terrible scheme and you can do a lot more both to increase your ad revenue AND please your ad-buying customers at the same time.
Your first problem is that all of your high-priced ads are on your home page or site entrance. You need high priced, high value ads on EVERY section of your site. With your home page, people just glance at it for half a second before going to the forums, stories, pictures/video, chat and the other pages. The total numbers may be lower on those other sections but THAT is where visitors spend their time and THAT'S where the advertising is the most visible and valuable.
The second problem you have is that you don't allow advertising customers to use targeted marketing. This is huge and even basic marketing principles will tell you how important this is. You have many diverse sections on your site including a forum, stories, ABDL products, cams/chat, Dear Daily Diapers, pics and video so why don't you let customers pay to selectively target their ads there??? This is absolutely infuriating. You have a golden opportunity to let customers pick the niche that they specialize in and advertise only on that section and yet you don't allow this. I'm not saying that your rotating ads or any sitewide ads won't be useful to some people... but you'll provide a much better service if you can allow customers to buy targeted marketing as well.
Again, I'm not trying to be mean here or ram something down your throats but I'm just incredibly frustrated at this ad scheme right now and trying to figure out how to buy advertising that will work for me.