The extent to which the receiver sees the source as knowledgeable and trustworthy to give information. A source Message characteristic which encompasses similarity, familiarity and likability. The source may be of 3 types: (i) Direct source: A spokesperson who delivers a message and/or demonstrates a product/service. (ii) Indirect source: A model who doesn’t actually delivers a message but draws attention to and/or enhances the appearance of the ad. (iii) Organization: The organization itself with the message to communicate.