There are growing discussions of social media influencers and their effectiveness in endorsing products. Further, recent policy regulations are requiring social media influencers to disclose sponsored content when using a form of native advertising. This research examined the effect of macro-influencers (high likes) and micro-influencers (low likes) and their disclosure of native advertising sponsorship on consumer evaluations of products. Results from a 2 × 2 experiment first show that consumers exposed to the micro-influencer condition report higher levels of product knowledge, and consumers exposed to the disclosure condition reported the products endorsed by social media influencers to be more attractive. The results also show that when exposed to micro-influencers who disclose, consumers have higher levels of purchase intentions than when exposed to macro-influencers who do not disclose, as well as higher purchase intentions than for posts where sponsorship is not disclosed by influencers. The important findings of this research for theory, practice and policy are discussed.