I love receiving affiliate commission sales notices that state how much I just earned from the sale of a product that I've recommended on my site.
But those that read “You have earned an affiliate fee of 0.00 USD for the sale of XYZ product on Wed Apr 6 2011 9:44:29 MST“, don't thrill me so much.
They make me sit up and take real notice and ask “Huh, WHY???“. (Imagine a really whiny voice – especially considering I received 2 of those notices within minutes that meant a loss of more than $100 in commissions. Grrrr.)
In this particular case, the answer was pretty simple.
The merchant had moved their program to another affiliate network and was no longer paying commissions on sales generated by affiliate links from their affiliation with the previous affiliate network.
Good grief! I thought I'd changed all those links!
Sure enough, a review through my various sites led me to the errant link quickly.
I changed it even more quickly.
Just one more reason to pay attention to your merchant's email announcements and make sure that your affiliate links are actually generating commissions!