Mapping the Business Functions of Social Media Marketing: A Five-Domain Systematic Evidence Synthesis

(1) Background: Social media marketing, the use of social platforms to build brand awareness, engage customers, gather market insights, distribute content, and drive sales has become essential to business strategy across firm sizes. (2) Methods: A systematic review of literature from Google Scholar, Semantic Scholar, and Scispace, published between 2020 and 2026, was conducted using PRISMA-based screening, yielding 14 studies for full-text analysis, a supplementary VOSviewer keyword co-occurrence analysis of study titles and abstracts was also performed. (3) Results: Five core domains were identified, expressed as each domain’s share of the 43 total domain-study codings across the 14 studies: brand awareness and promotion (26%), customer engagement and interaction (30%), market research and insights (9%), content creation and distribution (14%), and sales and lead generation (21%). Customer engagement and brand awareness were the most consistently supported outcomes, while market research remained comparatively under-investigated; the keyword analysis independently corroborated this gap, surfacing no cluster corresponding to market research or content creation. (4) Conclusions: Social media effectively drives brand visibility, engagement, and sales through quality content and consistent interaction, though its use as a market-intelligence tools remains underutilized. Businesses should prioritize content quality, platform-appropriate strategy, and internal social media capability, while future research should address this documented gap across broader contexts.