Got a call from this number, call seemed automated (interactive voice response/IVR style), they said I was entered to win a prize and wanted to know if I have a visa, mastercard, discover, or american express.  When I asked what 1+1 was the response was "it sounds like you're not interested, let me put you on our do not call list and disconnect."

Sounds very much like a scam to me.  I'll be blocking the number.