If I'm going prospecting, it's obvious I need jeans and pickaxes, and obvious that Levi can make more of those than he could use in prospecting himself. Levi is

If I'm going prospecting, it's obvious I need jeans and pickaxes, and obvious that Levi can make more of those than he could use in prospecting himself. Levi isn't telling you you'll get rich from his jeans, he's just selling you what you know you need if you are prospecting. It's not obvious why I need your How to Mine for Gold and Riches book and why you can't use that information to get rich youdser, if it's good information.