Celebrities or ordinary people who have a significant number of followers in social media and have power to influence these followers defined as “influencer”. “Influencer marketing” is a marketing strategy that brings together these individuals, who are influential with their posts in online environments with the target audiences of brands in the form of sponsored content. Although its first example was seen in the 18th century, the improvement of influencer marketing began with the emergence of blogs, and influencer marketing started to rise with social media platforms. Influencer marketing, which takes advantage of the power of word-of-mouth marketing and increases this power with social media, has become a leading marketing strategy today. Influencers are divided into different groups, including celebrity influencers, mega influencers, macro influencers, micro influencers and nano influencers, depending on the number of followers and the engagement rate. When determining the appropriate influencer for their campaigns, brands should consider the influencer compatibility with the campaign message, the characteristics of the existing followers, the number of followers, source credibility and content value. After the influencer is identified, the campaign is started by choosing one of the methods such as sponsored sharing, brand ambassadorship, product review, content co-creation and then appropriate compensation type is chosen. Compensation type may not only be monetary such as pay per transaction or pay per lead but also other methods such as free product and services or intangible compensation. During the campaign, the influencer is supported to communicate effectively and proactively and thus become a reliable source of information. In the next stage, interaction is monitored and finally the real outputs of the influencer collaboration (engagement rate, return on investment, etc.) are measured.