"a journey into sales [products]"

At the end, John says he's "100 times better" at sales now than when he started. I didn't read much about things he did to improve his personal selling skills, just how certain products have grown sales at Monitorbook. I don't doubt that he's improved, just would've liked to read more about his sales skill improvement than the products he discovered. Or maybe his point is anyone can be a good salesman because these tools are out there for anyone to use?