1. A method comprising: sending a listing, the listing comprising public contact information; sending an option to map the listing to a user account, the user account identified by a user identifier; receiving data indicating selection of the option to map the listing to the user account; generating a verification code from the user identifier and a listing identifier, the listing identified by the listing identifier; causing delivery of the verification code, wherein the delivery is made to a destination that is based on the public contact information; receiving an inputted code; determining whether the inputted code matches the verification code; mapping the user account to the listing in response to determining that the inputted code matches the verification code; wherein the method is performed by one or more computing devices.