Do pre-loaded credit cards work on the Wii Shop Channel?

Does anyone know?

I don't see any reason why not Rukiafan. As long as it has an account number and security code on the card, it should work. There should be an expiration date present too.

Thanks my friend.

How do pre-loaded credit cards work exactly? Is there interest or a service charge for each order?

I'm pretty sure they're just debit cards, with however much you pay charged onto them. No interest, but you can only pay with what you have.