I almost gave this a lower rating because it is a challenging read - I thought a couple of times of packing it in halfway through which never makes you feel good about a book.
Thankfully I didn't, because it is a difficult subject matter, but there aren't any problems with the writing or content.
I have had to over it quite a few times to "get it" and there are still things I don't fully understand, but at least I can replicate to get results. Some readers might be able to grasp it first time, but I think many won't unless they already know about things such as Clustering and Exponential Smoothing.
If you are looking for a basic intro to Data Analysis you should avoid this, but if you are looking to really get stuck in, then buy it. Be warned what you are letting yourself in for: just browsing it or reading once and putting on the bookshelf will be of no use whatsoever. I've spent at least 30 hours on it so far.
Overall the content and the ideas are brilliant, and the guy is really really funny - still doesn't make it any easier.