IntroductionAdvertising and Public Relations start their mission from focusing on feelings of their audiences to find a client or to change its relations, attitude or thinking. These two subjects have many similarities, but they are different for whom the information intended to reach and how it should affect the target audience. Until recently, advertising was an instrument to inform the audience to find clients. Today, advertising becomes more targeted, cost-efficient and search oriented. To illustrate, Google, Yandex and other search engines offer unique advertising opportunities to access clients worldwide, which no other media can offer for available budget and for 24 hours a day.Concerning public relations, previously it was an instrument to work and communicate effectively with public. Today, public relations covers areas related to leading and changing public views and thinking. For example, Facebook, LinkedIn, Twitter and other social media allow organizations not only access, communicate with the public but also tackle key issues, access new social groups and constantly involve them to change their thinking, attitudes and character. As the first step to define the challenging issues and implications of the two subjects, it is necessary to overview the instruments of advertising and public relations from angle of historical changes. Therefore, Table 1 outlines major instruments of advertising and public relations of the past, present and in the future. Table 1 shows main instruments of advertising and public relations. Analyzing the Table, one can conclude that advertising and public relations are gradually changing from mass to target media, and in future, it will change to interactive target media. This is one of the challenging issues from technological point. Companies, which will be first to acquire those technologies will have competitive advantage and can grow their audiences enormously. Analysis supports that the effects of changing technology are of great concern to the advertising and PR industries [1]. The review of literature and papers will provide a broader scope of knowledge and understanding of advertising and PR effects on people, their behavior and the future. According to marketing theory [2], advertising and public relations is a part of the promotion mix, which relates to persuading audiences to buy products, concepts and ideas. Here [2], advertising defined as any paid of nonpersonal presentation and promotion of ideas, goods or services whereas public relations defined as nonpaid, nonpersonal stimulation of demand for a product, service or business unit by planning significant news about it or a favorable presentation of it in the media.However, which is the best tool to sell products, advertising or public relation? There is no simple answer as they are part of the marketing field which requires many other factors to be taken into account. Bittlingmayer G [3] suggests that when looking at the problems the firms faces in promoting their goods, one can understand why advertising us...