In today's competitive globalized sports market, digital tools are crucial for sports organizations to connect with fans and stakeholders. Social media has emerged as a fundamental tool, with engagement serving as a critical metric. However, optimal use of social media in sports remains unclear. This study aims to descriptively and comparatively analyze the engagement generated by social media posts of elite football clubs across Europe, South America, and North America. The central research question is: What are the main characteristics of Facebook, Twitter, and Instagram posts from elite football clubs that generate the highest engagement? Grounded in relationship marketing theory, the study uses a content categorization approach to identify key elements of high-impact social media posts. By analyzing these elements, the study contributes to the literature on sports marketing and provides practical implications for football club managers to improve their digital strategies and enhance fan loyalty.

The literature review highlights the significant role of social media in various sectors, including sports, for marketing, brand building, and consumer engagement. Social media's interactive and visual nature makes it especially relevant for the emotionally charged sports industry. Studies have shown the impact of content type, format, and platform on fan engagement, but a gap remains in understanding the optimal use of social media across different regions. Relationship marketing theory provides the framework for understanding how social media can foster long-term relationships between football clubs and their fans, creating value for both parties. The review explores previous studies on social media use in sports contexts (e.g., Facebook, Twitter, Instagram), highlighting the need for further exploration, particularly regarding content categorization and engagement.

This exploratory, descriptive, and comparative study employed an observational method and content analysis techniques. A non-probability sample of 16 elite football clubs (6 from Europe, 6 from South America, and 4 from North America) was selected based on various ranking criteria. Data were collected from Facebook, Twitter, and Instagram posts over a 45-day period using Fanpage Karma software. An observation instrument, based on Solanellas et al. (2022) model and validated by nine experts through semi-structured interviews, was used to categorize posts into five dimensions: Sports, Institutional, ESG (Environmental, Social, and Governance), Commercial, and Marketing. Nine format combinations were also identified. Intra-observer reliability was assessed using the Kappa coefficient (0.949). Engagement was calculated using formulas adapted from Fanpage Karma (2022) and Rival IQ (Feehan, 2023). Data were analyzed using t-tests, ANOVA, chi-square tests, and correspondence analysis using SPSS 27.0.

Of the 19,745 posts analyzed, Twitter accounted for 64%, Facebook 22%, and Instagram 14%. However, Instagram showed the highest average engagement (1.873), followed by Facebook (0.112) and Twitter (0.045). Across all platforms, "Marketing" and "Sports" posts were most frequent. "ESG" posts were less frequent but showed engagement similar to "Marketing" and "Sports". Engagement varied across platforms and content dimensions. On Facebook, "Commercial" posts showed statistically significant higher engagement than "Sports," "Institutional," and "Marketing" posts. On Twitter, "Institutional," "ESG," and "Commercial" posts showed the highest engagement, with "Institutional" showing statistically significant higher engagement than others. On Instagram, "Marketing" posts showed the highest engagement, with statistically significant higher engagement than other types. Regarding formats, "Text/Image" and "Text/Video" were most frequent across platforms, but "Image" consistently showed high engagement, especially on Instagram. Correspondence analysis revealed associations between content dimensions and formats.

The findings highlight that post frequency does not directly correlate with engagement. Engagement is influenced by content type, format, and platform. The results demonstrate the importance of a strategic approach to social media management in sports, tailoring content and formats to specific platforms and audience preferences. Facebook presents opportunities for leveraging "Commercial" content, while Twitter shows potential for "ESG" messaging. Instagram excels in "Marketing" content, suggesting its suitability for visually appealing and emotionally resonant posts. The study's findings contribute to the understanding of fan engagement and provide practical implications for sports marketing strategies.

This study offers a novel approach to analyzing social media engagement in football, providing a practical tool for measuring engagement and identifying optimal content strategies. The findings suggest that a diversified approach, tailoring content and formats to specific platforms, is key to maximizing engagement. Future research could explore other social media platforms, examine engagement across different seasons, and investigate the impact of factors like club size and financial resources on social media success. The development of AI-driven prediction models for engagement would also be a valuable contribution.

The study's limitations include a relatively small sample size of football clubs, limited to three social media platforms, and a short observation period. While the sample represents major football clubs across three regions, further research could involve a larger number of clubs and a broader range of social media platforms. The 45-day observation period might not capture the full spectrum of seasonal variations in content and engagement.