I think it's likely that you're missing a layer. The book is really just marketing for the DHH/37signals/RoR brand. Developing that brand makes people more lo

I think it's likely that you're missing a layer. The book is really just marketing for the DHH/37signals/RoR brand. Developing that brand makes people more loyal to their products and ecosystem, which probably makes them a lot more money over the long run than book sales.