Facebook is a marketing communications platform. what messages are being communicated by Facebook is what you're investigating. your framework has to indicate that.
I mainly used hierarchy response models (refer to my ResearchGate profile and articles), such as the hierarchy-of-effects (Lavidge & Steiner, 1961), but there are many others such as: Advertising value model (Ducoffe, 1995); Theory of Diffusion of Innovations (DIT) (Rogers, 1995); theory of Task-technology fit (TTF) (Goodhue & Thompson, 1995); Theory of Reasonable Action (TRA) (Fishbein & Ajzen, 1975); Theory of Planned Behavior (TPB) (Ajzen, 1985, 1991); Decomposed Theory of Planned Behavior (Taylor & Todd, 1995); The Technology Acceptance Model (TAM) (Davis, Bogozzi & Warshaw, 1989); Final version of TAM (Venkatesh & Davis, 1996); Technology Acceptance Model 2 (TAM2) (Venkatesh, & Davis, 2000); Unified theory of Acceptance and Use of Technology (UTAUT) (Venkatesh, Morris, Davis & Davis, 2003); Technology Acceptance Model 3 (TAM3) (Vankatesh & Bala, 2008), whatever you feel fits your study best.
Chanthinok, K., Ussahawanitichakit, P., & Jhundra-indra, P. (2015, July). Social media marketing strategy and marketing outcomes: A conceptual framework. In Allied Academies International Conference. Academy of Marketing Studies. Proceedings (Vol. 20, No. 2, p. 35). Jordan Whitney Enterprises, Inc.
Littlewood, K., & Bick, G. (2015, July). Developing the social media value chain: A conceptual framework for the measurement of social media. In Proceedings of the 2nd European Conference on Social Media ECSM (pp. 297-305).
Ngai, E. W., Moon, K. L. K., Lam, S. S., Chin, E. S., & Tao, S. S. (2015). Social media models, technologies, and applications. Industrial Management & Data Systems.
Holsapple, C. W., Hsiao, S. H., & Pakath, R. (2018). Business social media analytics: Characterization and conceptual framework. Decision Support Systems, 110, 32-45.