I think maybe 3 is a little bit narrow. I agree that it needs something that sets it apart from the giant online tubes where all books come from but it doesn't

I think maybe 3 is a little bit narrow. I agree that it needs something that sets it apart from the giant online tubes where all books come from but it doesn't necessarily have to be as much a specialty, it can be an editorial perspective. For instance, one of my favorite book shops ever: Green Arcade in downtown San Francisco. It has a pretty general selection but all somewhat skewed to a particular social perspective. I'm not sure I'd call this specializing per se as adding a human touch that, if you agree/are aligned with his perspective on things, will allow you to have a lot more faith in the book you're about to drop $30 on.