I think there are three types of calls to action which affiliate program managers and merchants should be using with affiliates.
The vast majority of managers and merchants use only one type (the first one, which also illustrated on the left), and this hurts the development of their affiliate program in at least the areas that the other two types cover.
1) Primary — calling to the the action you want them to take in response to an outgoing recruitment email or when they visit your affiliate program bio page (you better have one). This may be contacting you about your affiliate program, or most typically, submitting their application to join your affiliate program.
2) Secondary — providing an alternative route of action for your prospective affiliates, or those of them that may not be ready to to take the primary action (concept explained here). Are you inviting them to contact you anyway, providing them with enough of contact info and motivators to get back with you? You could also include an offer to at least exchange links, or a hint at the fact that you may be open to other partnerships (e.g. a synergy of a placement fee + a CPA model).
3) Post-primary — here I imply the call to activation you should have in the very approval email (more here) you send to the affiliate that has just been accepted into the program. Examples of motivators on the level of post-primary calls to action would be a commission bump, a cookie life increase or a monetary bonus in exchange for them putting your links up on their websites.
Are you as an affiliate program manager using all 3 types? If you aren’t, I strongly encourage you to change this today. It won’t take more than 15 minutes of your time to put the missing calls to action into the places where they belong.