Zzounds Affiliate Conversions

Has anyone any experience of Zzounds affiliate program and specifically whether Zzounds are any good at converting the targetted clicks you are sending through to them.

My guitar reviews site has sent then over 400 clicks for the past few months, all targetted traffic, and they haven't converted a single one, not even for a set of strings. My traffic is 99% US as well so it's not international traffic being sent through.

Has anyone had any success with these guys or should I look at the competition in Musician's Friend etc.?

I haven't used it but I've heard nothing but good things about it from others.

Maybe a case of generating more clicks to test it out fully before I jump ship.

One good thing about Zzounds is that they have a 60 day affiliate cookie as opposed to Musician's Friend which has cut theirs to 14 but it's not much good if people are clicking on someone else's affiliate link before they make a purchase.