Keep as many reputable affiliates listed as you can.
If I come to your door holding two or three chocolate bars in my hand and tell you, “this one is the best bar ever! You should buy one!” Do I sound credible, or desperate?
Then again, if I come by with 20 different bars in a box and point to one and say, “this one is the best eeever!” doesn’t that make me look a lot more credible, and you a lot more likely to buy the bar I recommended?
It is natural to believe that someone who is selling a product knows something about it – or at least more than you do. The more products (or affiliates) I sell, the more knowledgable I will appear, and the more credibility I will have in labeling one or two as “the best”.
Of course I have to be prepared for the fact that you might just not like my taste, and choose to buy my “worst” chocolate bar. As long as that bar isn’t poisoned – or in the case of an affiliate, a fraud – I shouldn’t mind. Overall I’ll end up selling more of my best earner, and still make at least make a profit from the others.
So like I said, the more good ones you can manage, the better.