Influencer marketing is developing relationships with industry experts and influential people to help brands achieve digital goals. It involves building relationships with brand advocates by providing them content to share, which increases positive sentiment. Examples include fashion bloggers reviewing new products, vloggers with large followings promoting brands, and collaborating with social media personalities to create engaging sponsored content across platforms like Vine and Tumblr. Choosing the right influencers requires knowing the target audience and campaign goals and researching influencers' social reach and previously created content. A contract should outline the partnership.