A method and system for alphanumeric identifier indexing for advertising with cloud computing. A cloud computing service is provided to process alphanumeric identifiers (e.g., mobile device identifier, social network identifier, etc.) and used to categorize and associate pre-determined advertising and/or dynamically generated advertising with the alphanumeric identifiers. When the alphanumeric identifier is received anywhere on a cloud computing network, pre-determined or dynamically generated advertising associated with the alphanumeric identifier is sent to a target device. The cloud computing service keeps advertising synchronized across all devices all alphanumeric identifiers and all logins owned by a user of the target device used from anywhere on the cloud computing network.