Have you noticed how Compete.com is positioning itself now? Here’s a screenshot I’ve just taken (emphasis, of course, mine):
This is, actually, not too surprising to see. What is surprising thought is that competitive intelligence and link building tools have taken so long to start selling themselves as powerful affiliate recruitment tools. They are actually really great for this. You can easily find the more popular websites in your niche (either by keywords, or by links to your direct competitors, or simply by weight in this or that vertical), and approach them with proposals to join your affiliate program. If you aren’t using any of them for this, you should.