they are trying to "give away" gift cards that you have to pay for shipping for. the guy seamed uneasy, impatient and hung up on me when I asked to be removed from his list. He also groaned when I was unwilling to give him my information.
One ring and a hang up. Scammer wants you to call back so he can hit you with his sales pitch or scam without violating Do Not Call regulations (he didn't try to sell anything when he called you and it's fine for him to try when you call him).