1. A message selection system comprising: a memory device configured to store message selection information, wherein the message selection information comprises a plurality of suggested messages, wherein each of the plurality of suggested messages is associated with one of a plurality of electronic channels of communication; and a processor in communication with the memory device, the processor configured to: receive a request from a marketing source during an active session between the marketing source and a user interface to determine a suggested message to transmit from the marketing source to the user interface over an electronic channel of communication from the plurality of electronic channels of communication during the active session between the marketing source and the user interface, wherein the request is based on input received from the user interface by the marketing source during the active session, and wherein the user interface is a marketing target, wherein the suggested message is configured to elicit a desired response from the marketing target during the active session; select, based on the request, a plurality of candidate messages for the electronic channel of communication from a plurality of messages included in the message selection information during the active session; during the active session, for each candidate message, generate a respective corresponding numerical score for each of a plurality of business objectives, wherein each numerical score is based on relationship unique to each business objective that includes factors associated with specific levels of response to an associated candidate message and an associated electronic channel of communication; select, based on the numerical scores, the suggested message from the plurality of candidate messages during the active session; and transmit the suggested message to the marketing source, wherein the suggested message is configured to be transmitted from the marketing source to the user interface during the active session.