Spontaneity can hurt.

I just spent about $160 sending two of each of these books to instructors at my old high school:

The Manga Guide to Calculus
The Manga Guide to Molecular Biology
The Manga Guide to Physics
The Manga Guide to Statistics

I included a note that I hoped one book would go in the school library, while the instructor would loan the other to students who it might help. (Not necessarily in the academic sense, but in the motivational sense; An interested and self-motivated student is a better student.)

I suppose the observation that more women than men would be interested in the manga is also a bit of a benefit to the fields as well. (Also, I suppose, a benefit to the male geeks that come after me...)