Purpose The purpose of this paper is to explore the application of advertising variation and repetition strategies in the context of communicating about social issues in least developed countries (LDCs). Design/methodology/approach Study 1 used a between-subjects experimental study using 106 students which were exposed to either the varied advertising condition (a negative appeal followed by a positive appeal or vice versa) or repetition condition (two negative appeals). In Study 2, a total of 111 students from Tilburg University and 95 students from Addis Ababa University participated in the study. A random ordering of experimental envelopes assigned the students to one of the following message order conditions (negative appeal–positive appeal, negative appeal–negative appeal, positive appeal–positive appeal and positive appeal–negative appeal). Findings Study 1 shows that for many social issues, an advertising variation strategy (a negative appeal followed by a positive appeal) is more effective than an advertising repetition strategy (two negative appeals) in terms of recall. Study 2 builds on these findings by differentiating between taboo and non-taboo issues. This distinction is important because many social issues, such as HIV, domestic violence and child abuse, for instance, are taboo in LDCs. Interestingly, the findings of Study 1 are reproduced for non-taboo issues but not for taboo issues. If an issue is a conversational taboo in a certain culture, then an advertising repetition strategy that only uses positive appeals is more effective than an advertising variation strategy. Research limitations/implications The use of students as participants may be a limitation of both studies. Because the reactions of students to specific message appeals may be age-related, concerns regarding the generalizability of the findings are justified. Originality/value Overall, the results of this paper provide useful information to social advertisers on when and how to use different types of advertising strategies in LDCs.

This article explores media preferences of advertisers in Least Developed Countries (LDCs) using the case of Ethiopia. Study 1 demonstrates that billboards are the most popular medium in an LDC. Study 2 builds on these findings and provides an explanation of why billboards are prevalent in an LDC. The most important reasons for using billboards include tangible response, media efficiency, location, visibility, and LDC-specific factors. Study 2 also provides an overview of managers' beliefs regarding billboard effectiveness. According to the managers in an LDC, the factors contributing to billboard effectiveness are clarity, name identification, location of billboard, visuals, readability, information, physical aspects, creativity, and integrated marketing communications. Finally, this article investigates the relationship between the reasons for using billboards and managers' perceptions of what makes them effective. Overall, these studies fill a void in the literature by researching issues that were less explored by earlier studies, particularly in the context of an LDC. Implications for marketing scholars and practitioners are delineated in the article.