My assumption is that it would be popular. So popular that the library would decide on sell a little snacks, sandwiches and soft drinks to earn a little money. And as the sale opens, they would realize that they get a lot higher profit on alcoholic drinks. And since they are selling alcoholic drinks, it's unresponsible to have them in the same area as the daily area with books and study groups. Then they open a new section, maybe in a new location. And to save money on labour, they drop the non alcoholic products.

Of course this is taking it a bit far, but my point is that such a service has incremental steps, where each step would likely give higher profit until it is just a pub.