Advertising in today's competitive market is one of the most important factors of the success and growth of organizations. The only way to survive in this market is to use the most effective advertising methods. The out-of-home media advertising creates a steady trend while transferring the message directly in all stages of advertising. Thus, identifying, highlighting, and prioritizing out-of-home factors would be very important, as they leave an impact on the minds of customers. In this research, we aim to prioritize the characteristics and the elements of the most important outdoor advertising tool, that is, billboard, which affects the mind of the audiences. The question asked in this regard is which of the elements of an advertising poster has a higher impact on the actual or potential audience. This impact has a direct relationship with customer purchasing behavior. Accordingly, this researcher aims to identify the outdoor advertising factors based on a questionnaire and interview with experts. The research population included advertising experts and metro passengers in Tehran. The results of the research showed that the elements related to the design and background, the elements related to brand identity, and elements related to content are the main factors affecting the minds of the audience.
