User-generated content (UGC) refers to brand-related content created by consumers rather than brands, often shared on social media platforms. As an innovative form of marketing, UGC allows brands to co-create with their audiences, fostering authenticity, community, and reach. This chapter investigates how brands encourage users to act as promoters on Instagram through UGC. Drawing on qualitative content analysis, it explores brand UGC strategies across sectors like travel, fashion, and tech, identifying key motivational techniques and interaction dynamics. While offering insights into brand-user co-creation, the chapter is limited by its platform-specific focus, brand selection, and static data set. Nevertheless, it highlights how medium-autonomy content, where users maintain creative freedom within brand-led initiatives, proves especially powerful. Ultimately, the chapter emphasizes UGC as a strategic tool for brand visibility, trust-building, and engagement in a participatory digital age.