1. A computer implemented method comprising: sending, by a processor, a first message to a first recipient's terminal, the first message including a first content selected from a database, the first content including: data for display within a display of a receiving terminal, and control data comprising data indicative of a user selectable portion within the display, wherein the control data, in response to selection thereof, is configured to cause the receiving terminal to formulate and transmit a response message to register selection of the user selectable portion, wherein the control data includes a ready-made response message that includes a source address, destination address and a content identifier that identifies the first content; responsive to receipt of the response message comprising data indicative of selection of the user selectable portion within the display, modifying, by the processor, an access status of the transmitted message, wherein the access status indicates that the user selectable portion of the first message was selected by the first recipient; identifying, by the processor, attributes of a second content, different than the first content; querying, by the processor, the database to identify previously transmitted content items having similar attributes to the identified attributes of the second content; determining, by the processor, that the second content shares at least a predetermined number of attributes with the first content; inserting, by the processor, the second content into a second message; and transmitting, by the processor, the second message to the first recipient.