This paper deals with influencer marketing on social media. This relatively new concept of marketing is growing rapidly and in just few years has reached market size of 14 billion dollars. Social media, in its young history, have transformed from platforms for communications and connecting with people to big marketing tool for many companies and brands. Today more than half of world population use social media which gives enormous market of potential customers for many companies. Influencer marketing represents collaborations with people who have the power of influence on social media for promoting the product or brand. Influencer is a person that has the power to affect the purchasing decisions of others because of his or her knowledge, position, authority, or because of the relationship with his or her audience. Influencers may differ according to number of followers or expertise but what makes them so successful is a word of mouth marketing that is based on trust and respect that affects on customers decision making. This paper will present Airbnb as example of good and PepsiCo as an example of bad influencer marketing strategy.