Q: What constitutes a healthy composition of an affiliate workforce (i.e. percentage of search affiliates, percentage of email marketers, percentage of Web site publishers)?
A: In my opinion, such a thing does not exist. I think it would be silly to base the affiliate recruitment in your affiliate program on any sort of quotas.
You would be limiting the affiliate program by doing this sort of thing.
The healthy composition of affiliates in your affiliate program is whichever breakdown of affiliate types enables you to have the most active and productive affiliates.
Obsessing about having 20% of one type of affiliate and 20% of another type of affiliate won’t accomplish anything for you.
Certain affiliate programs tend to attract specific types of affiliates, based on the products and services available through them.
So focus on the types of affiliates that are performing well for you now and try to recruit more in that area.