Within your terms and conditions, you need to define what can and cannot be promoted through PPC. The most obvious restrictions are brand terms and misspellings. So one of your objectives could be to increase your visibility on search engine affiliates, and you can do this by targeting only long tail keywords. Other things to consider are whether affiliates can link PPC directly to your site and whether they can use your URL in the ad copy. These are decisions you need to state in your terms and conditions.
Affiliate marketing overlaps with other Internet marketing methods to some degree, because affiliates often use regular advertising methods. Those methods include organic search engine optimization (SEO), paid search engine marketing (PPC – Pay Per Click), e-mail marketing, content marketing, and (in some sense) display advertising. On the other hand, affiliates sometimes use less orthodox techniques, such as publishing reviews of products or services offered by a partner.