@Rdio_Ch That depends. If it makes the difference between keep a client and losing him because he can get a better deal elsewhere, you're better off giving a discount than to lose the client completely.
I'm just looking at it from a customer's standpoint, because I've been one for years before I got in the hosting business. Something Godaddy did/does really well, is retain customers by giving them discounts in pretty much every renewal email they send. "Oh, 20% off? Might as well stay" instead of "I wonder if I can get a better deal elsewhere"..
I'm really on the fence on this topic. Obviously, nobody is in business to lose money, but are you losing less by diving a (small) discount on renewals?