As a high school student with final math exams coming up soon, large gaps in my mathematical knowledge and a bunch of useless textbooks, I went for the "buy now" button just after reading the "I will teach you everything you need to know about equations, functions, vectors, limits, derivatives, integrals, forces, accelerations and optics" tagline.

Then I saw that there is no e-book option. It's 2013. Get with the times.