$3754 in one month from 3 books as a college student

Samuel is a 22 year old university student from Switzerland, who took a year off from school to focus on publishing and he shares what he did to make $3754 in a single month from his 3 books. Samuel talks about what it was like publishing his books with English as his second language, and why his two low content books did even better than his high content book. Let's just say that it has to do with customer research