An innovative, technology-enabled elementary school literacy program was implemented in a large urban school district. The program revolved around having student–adult pen pals read the same books and correspond about them. Statistical comparisons showed that program classrooms outperformed students in comparison classrooms on the SAT-9 standardized test of reading achievement. Analyses of interviews, survey results, and classroom observations were conducted to discern factors associated with program success. It was found that the effects of the program could best be understood in terms of three features: practices, principles, and persistence. The specifics of each of these factors are discussed in detail.