According to commentators, the cultural impact of Nancy Drew has been enormous. The immediate success of the series led directly to the creation of numerous other girls' mysteries series, such as The Dana Girls mystery stories and the Kay Tracey mystery stories, and the phenomenal sales of the character Edward Stratemeyer feared was "too flip" encouraged publishers to market many other girls' mystery series, such as the Judy Bolton Series, and to request authors of series such as the Cherry Ames Nurse Stories to incorporate mystery elements into their works. The "Nancy Drew Mystery Stories" series and other girls' series books faced criticism for the formulaic nature of their plots and the poor quality of the actual books.