The book has some good insights and was a good short read. The book promised free online access to the interviews and other learning material via the 50 Lessons website, but that's a lie. It probably was true, but Skillsoft acquired the properties of 50 Lessons and it's no longer available freely. I spent an hour looking to see if you can even purchase the material but could find it nowhere. The only think I got a vague idea is that I needed a Books 24/7 subscription to access it, but I'm not sure.
The content was good, but you can get similar value from reading the blogs at HBR.org.