First off, that criterion isn’t a deal-breaker. The majority of sales of my own info products have come from paid or organic traffic, not affiliates (but that’s largely because I’ve been too lazy to reach out to potential affiliates!)
If you do want to find affiliates, there are a couple of ways:
1) Look on the Clickbank Marketplace for products that are complementary to the product you want to create, and approach the product owners to be your affiliate.
For example: my main info products have been in the sleep disorders market. I know from being in that market for a long time that people who have sleeping problems tend to be (a) overweight, and (b) older.
So what I could do is search through the Clickbank Marketplace for products that relate to (a) weight loss, and (b) problems associated with old age. Then I could contact those product owners and pitch them on being my affiliate, by sending out an email to their list promoting my product, etc.
I’ve actually done this a couple of times with a CB product owner in the back-pain niche, and it worked out really well. They simply sent an email to their list with a link to my sale page, and I got a bunch of sales. But it takes work to develop the relationships – which is why I haven’t done it very much (I’ve spent more time learning paid traffic and SEO).
2) Similar to (1), do Google searches for sites in niches that are complementary to yours. Target the sites that aren’t too big and won’t get back to you (e.g. in health niches, I wouldn’t contact sites like WebMD.com, because they’re part of a large corporation and probably wouldn’t even reply to me).
Blogs that are run by a single person but get a lot of traffic are a great source of potential affiliates, because you can actually make contact with the blog owner.
Hope that helps. If you have any follow-up questions, fire away!