Expressing Demands or Offers: How to Promote Volunteering Using Visual and Verbal Appeals

Due to an increased competition for volunteers, nonprofit organizations have intensified efforts to recruit members as volunteers. But how to effectively persuade members to volunteer using visual communication? Research suggests that images are most persuasive when they demand something from the viewer. A demand is expressed through the depiction of a person who directly gazes at the viewer, whereas an offer is expressed through the depiction of a face with an averted gaze. Demands and offers can also be expressed verbally. A verbal demand is articulated through commands, whereas a verbal offer is conveyed through statements. This study examines whether NPOs should address their members using demands or offers and whether correspondence between image and text increases persuasion. An experiment among 205 members of a Swiss NPO finds that direct gaze images are most effective. However, image-text matching increases persuasion for campaigns that feature an averted gaze image.