Purpose: Echo chambers in social media emerge through the convergence of algorithmic content distribution and users' selective engagement patterns, simultaneously presenting opportunities and risks for digital branding. While brand-audience alignment can enhance engagement, loyalty, and positioning, reduced informational diversity may foster cognitive biases, polarization, and erosion of trust. Despite growing scholarly interest, no integrated framework exists for identifying the factors shaping this phenomenon in SMEs' digital branding context. This study systematically extracts and categorizes these factors and develops an evidence-based conceptual model.

Method: This research applies the seven-step meta-synthesis method of Sandelowski and Barroso (2007). A systematic search across domestic databases (SID, Magiran, Civilica) and international databases (Scopus, Web of Science, Google Scholar) was conducted. Inclusion criteria comprised conceptual relevance to echo chambers or information homogenization, connection to digital branding or consumer behavior, full-text accessibility, and adequate methodological quality. From an initial pool of 90 sources, 68 high-quality sources were ultimately selected following staged screening and full-text quality assessment. Key propositions were extracted, overlapping concepts merged, and iterative synthesis continued until conceptual saturation was reached.

Findings: Six core thematic dimensions shaping echo chamber formation in SMEs' digital branding were identified: algorithms and informational filtering mechanisms; cognitive biases and consumer behavior; digital branding practices in SMEs; social interaction and collective feedback; brand orientation and brand mission alignment; and homophilic behaviors and informational resource limitations. Personalization systems, targeted advertising, and algorithmic recommendations interact with confirmation bias and selective exposure to foster informational homogeneity around brands, while brand narrative design, customer experience management, and brand community development shape the intensity of this process.

Conclusion: The proposed conceptual model offers an integrated perspective on the interplay among platform algorithmic architecture, consumer behavioral patterns, and digital branding strategies in SMEs. SME managers should enhance algorithmic literacy, balance content repetition with diversity, actively manage brand communities, and mitigate risks of informational closure and polarization. The framework contributes to advertising and sales management literature and serves as a strategic roadmap for brand communication in digital environments.