I purchased the e-book 2 years back when it came out and it took me until now to read/practice it. I must say if I read this book when it came out, some of the concepts would have been clearer much earlier. I recommend this to anyone who wants to brush up the math concepts in calculus/statistics/probability and linear algebra before diving into the details.
It is a nice textbook for someone with a Humantities background, featuring a detailed presentation of terms and concepts as well as understandable examples - all in plain English!