This document summarizes a literature review on how social media influencers have replaced traditional spokespeople in cosmetics advertising targeted at millennials. It discusses how media-multitasking, electronic word of mouth, and self-performance on social media platforms like YouTube, Instagram and Snapchat have influenced advertising strategies. Social media influencers are everyday consumers who shape attitudes through their social media content. They have helped bridge the gap between advertisers and millennials by providing a more personal and trusted endorsement compared to celebrity spokespeople. As the use of these influencers increases, it could significantly impact millennials' purchasing habits over the next ten years by empowering them as more educated consumers.