An influencer is someone who can influence the purchasing decisions of others because of their knowledge, authority or relationship with people; they tend to specialize in a specific niche in which they are expert and actively engage. A social media influencer is someone that does this on various social media sites and that attracts an audience of followers that are interested in their opinion.
These people have built a reputation for their knowledge, expertise and unique style when discussing their niche. They post content regularly on their preferred social media sites and create significant followings of engaged, enthusiastic people that trust them and pay close attention to what they have to say. Brands use social media influencers to reach customers because they are perceived as honest and authentic and are seen more as someone that is advising the customer rather than pushing a marketing message.