Purpose: The aim of this study is to identify and prioritize appropriate digital marketing tools for public libraries’ customer development.

Method: The present study was conducted in a combination of qualitative and quantitative methods. In the qualitative part of the research, in-depth interviews were conducted with 7 experts using a grounded method. The components were obtained from the analysis of these interviews, and a researcher-made questionnaire was designed based on both existing and desired situations. The research population in the quantitative section includes all marketers, information science specialists and librarians working in public libraries in Tehran. sampling was done randomly. Regression to the mean method was used to reach higher priority components,

Findings: The findings from the qualitative part locates 39 digital marketing tools that formed the items of the researcher-made questionnaire. In the quantitative part, the factor loading analysis of the components shows that all dimensions and tools of digital marketing in public libraries are effective and meaningful from the perspective of the community of experts. Using the Regression to the mean method, the tools that are both highly important from the perspective of experts and are currently among the most used by librarians were identified. Finaly The obtained tools were located in the content marketing tool matrix.

Conclusion: Libraries can focus on the tools suggested in this study to acquire new customers. Using a content marketing matrix reduces the complexity of working with these tools so that librarians can easily maintain their focus on the marketing.