This is a TRULIA scam. Caller is from the Colorado office of Trulia.
BEWARE. DO NOT GIVE THEM YOUR CREDIT CARD NUMBER.
If you give them your credit card number, they will keep making unauthorized charges every month after the first charge. They will say that you subscribed to their services when you paid for a one-time service only and then they will refuse to give you credit to refund your money.
The only resort you will have is to call your credit card company to complain and change your credit card number.