Brett, no idea, but I think the article still has some relevant content.
Woz, I'll try... It's funny, a lot of this I saw as an affiliate, but just now see from the other side.
Those that can produce are well worth whatever extra energy/commissions you can afford.
The 80 20 rule doesn't apply. The percent that actually produce are much lower.
Your competitor's affiliates are either happy with your competitor or not. In either case they can be swayed, but it's not an easy proposition to sway a happy affiliate, so try your weaker competitors first.
Top search results in competitive niches are often top earning affiliates of other merchants.
Top earning affiliates may want you to prove yourself and your program before they get involved.
Top earning affiliates are well equiped to compare programs. Give them all the info you have available. The selling point for them could be commission, conversion, report quality and flexibility, responsiveness, tier structure, etc. The bit you leave out is the bit that may cost you an affiliate.
Program management is a marketable skill in today's economy... ;)
Sorry, there was a lot more info than I've captured here.