Social media influencers have become increasingly important in the last years. Influencers, that is, individuals with a large number of followers on social media, filter information, advertise products and services, offer advice, and promote political opinions with a significant impact on a broad audience. Nevertheless, their actions have remained largely unregulated and overlooked in the literature. This paper offers an exploratory analysis of this phenomenon and delves into the regulatory challenges resulting from the activity of social media influencers. It fills an important gap in the academic literature by providing an interdisciplinary analysis of a phenomenon with growing societal relevance. Given their large audiences, influencers are very effective not only at creating online engagement for the companies that employ their services, but also at manipulating their followers’ opinions and transactional behavior, as the latter do not always distinguish between genuine and sponsored marketing advice. Although advertising regulations include endorsements made on Instagram or Youtube by ‘prosumers’, influencers appear to disregard these regulatory limits and national regulators have experienced difficulties in safeguarding their enforcement. In this context, average social media users are at an ever-greater risk of falling prey to inconspicuous commercial interests. This paper also introduces an interdisciplinary project that brings together insights from media studies, law, communication science and empirical legal studies, dealing with themes such as social media, influencer marketing, free speech, gig work, platform governance, and consumer protection.