Marc Andreessen: "Tremendous"
Naval Ravikant recommended Poor Charlie's Almanack on Twitter.
Patrick Collison included this book on his list of recommended books.
Peter Thiel: "Hamilton Helmer understands that strategy starts with invention. He can't tell you what to invent, but he can and does show what it takes for a new invention to become a valuable business"
One of the books Keith Rabois recommends for entrepreneurs.