Wil Wheaton also makes a solid observation about retail and marketing. I know this world well from the inside, and would advise you to follow his lead. As Nancy put it... "Just say No!!"
"She looked back at me, blankly, and said, "Can I have your ZIP code, please?"
"No," I said. (You see, it starts with the phone number at Radio Shack, then it's the ZIP code everywhere else, and before you know it, we're giving them DNA slides and submitting to retina scans. We've got to draw the line somewhere, people.)
"Whatever," she said, and typed in the local ZIP code. We completed our transaction, and I walked out of the store."