Yours is such a common issue. It's too bad no one on this forum has answered after two weeks. Other forums (search google) are more focused on affiliate issues than WebmasterWorld these years. I recently posted a question in this forum and got no replies. It is what it is.
One suggestion is to use PPC because your product and your audience of affiliate publishers is very narrow. That should produce a high ROI and CR for your PPC ads.
Second, advertise in trade journals (online and print) for your product.