I'm on the "no cards" side of the equation and I'm amazed how often I'll get argued with on why I want to join their clubs. I just smile and say I'm happy to pay full price since I come here so rarely and buy so little and that I've learned from experience I don't keep track of cards well nor do I wish to carry them with me. Also, no -- I don't want to give them ways to contact me and/or sell that email address or whatever either.
That goes for all businesses. I have never ever given out my cell number to anyone I don't personally know for example and haven't given out my home phone number in at least a decade -- and that includes stupid Comcast who almost every time I log in to my email that they want more information from me. They are not going to get it! I don't give out my email, and I do not sign up for sites that require me to register first to even look at them. Nope, Zulily, keep your deals to yourself. I know a lot of your are on Pinterest, but I'm not going there either.