Also, when looking for affiliates, look at the paid ads for CB products in related niches. Let's say you have a fitness product and you're looking for affiliates. Go through and search for affiliates that are promoting using PPC/YouTube/SEO/whatever in your niche AND similar niches like weight loss, muscle building, yoga, etc.
This can be expanded on. Think about what your target demographic is. Is it females aged 35+? Males aged 18 to 25? What else do they like?
For example, if its females aged 35+ then you can check out sites in other niches they may go to like crafting, parenting, flower gardens or whatever-the-hell else women that age do for fun.
If you have a "ab" product that's geared towards males in their twenties, approach site owners that cater to that niche as well.
I've grabbed up affiliates that run gaming sites for fitness products and affiliates that run Etsy sites for fat-bitch-weight-loss products. You never know how something will convert unless you test it. And even if it BOMBS for that affiliate on that site, you never know if they have 100+ more sites, a dozen or so which may fit your product and convert perfectly.
Basically, what I'm saying is to not hide behind your keyboard. Get out there and mingle. When's the last time someone called you up on a professional basis and said:
"Hey i like your site! It ranks well for keyword a, keyword b, and keyword c. I see you did a lot of work to it and i really love how the header looks. did you design that? sweet! speaking of which, i have this new CB product with a 160 x 600 banner already made up that would look really good in your sidebar where those stupid Adsense ads are. can i send it over? Yes? Awesome! Aw, that's sweet! I love you too! blah blah blah...!
More likely than not, if you did your research on the site you may know more about what the site ranks for than the guy that owns it. At least HALF the time I actually call someone up, I surprise them by telling them they rank high for a popular keyword they never even thought about. No shit. True story.
When you reach out to someone like this - you know, other than blasting generic emails - and they respond well (they usually do), it's often the start of a beautiful relationship. You guys will be drinking champagne out of strippers' shoes together in no time.