If the bookstore does not want people reading while sipping on coffee in their store, then why do they have a coffee bar, and easy chairs placed in reading nooks throughout the store?
The reality is that few people are going to read the whole book there at the store. And if it's good, they'll buy it. And even if they don't, people like me who go in and drop $200 on books because we're book nerds will make up for it