Key opinion leader (KOL) marketing involves brands collaborating with individuals who possess expert knowledge on a subject related to their products. While most KOL marketing occurs online, it has roots in celebrity marketing and has existed alongside experts for a long time. The distinction lies in expertise. Working with a football star to promote clothing lines is celebrity marketing, but it becomes KOL marketing if they have expertise in sports fashion or promote products related to their expertise.
Brands often use academic professionals and scientists, assuming they have qualifications and their own audience. Successful KOL marketing requires influencing behavior, making it a pure form of influencer marketing. However, not all influencers possess sufficient expert knowledge beyond communication skills.