The benefits to readers in a summer reading program include:
And it being summer, the program can just be good fun and provide an opportunity for family time.
Citing numerous benefits of summer reading programs, the ALA Council adopted the Resolution on Ensuring Summer Reading Programs for all Children and Teens (PDF) at the 2010 Annual Conference urging "Library Directors, Trustees, School Board members and supervising government bodies to insure that their libraries are provided adequate funding to ensure that their summer reading programs for all children and teens are maintained."
Talking points for the benefits of summer reading, Why Public Library Summer Reading Programs Are Important (PDF), have been made available by the Wisconsin Department of Public Instruction. A more comprehensive look on the topic, along with a bibliography, can be found on their web site at Literacy Research.
There are also public relations benefits of attracting new readers, maintaining or building a library presence in the community, and keeping or building traffic for the library. Over the years, many libraries have entered their summer reading program into the John Cotton Dana Library Public Relations Award, provided in conjunction with the H.W. Wilson Foundation, EBSCO, and the Library Leadership and Management Association (LLAMA, a division of the American Library Association).