The attitudes and persuasion literature has extensively examined what makes a message influential, paying much less attention to what makes someone communicate that message in the first place (i.e., engage in attitudinal advocacy). In addressing this, the present research first makes a novel distinction regarding the type of advocacy (requested versus spontaneous). Then, we examine how one's perceived attitudinal base (affective or cognitive) influences intentions to engage in each type of advocacy. Across six studies (four correlational and two experimental, n=1040), this research demonstrates two consistent patterns: perceiving one's attitude to be more cognitively (vs. affectively) based results in greater willingness to engage in requested advocacy, whereas perceiving one's attitude to be more affectively (vs. cognitively) based results in greater willingness to engage in spontaneous advocacy.