[Photo provided to China Daily]

On July 20, four years to the day when the shop opened, half of about a dozen desks in its reading-for-free zones were occupied. Outside, the din of the nearby Shichahai areas and hutong were dying down; inside, some were reading the shop's books and some were working or studying.

One shop assistant and one guard were on duty, their shifts due to end at 8 am the following day, and they seemed happy to offer assistance to customers. In these shops that help can go beyond locating books, because apart from having cafes, and selling gift items, some are turning into venues for all kinds of social activities.

In Page One Qianmen there are occasional mini concerts in the evening.

"For 24-hour bookstores, the operating challenges run into the second half of the night, says Zhang Lei, also known as San Shi, a veteran bookstore planner and critic. "The solutions include running multiple businesses.

"Midnight bookstores are like large study areas, a third space in addition to the home and the workplace. People actually do a lot of things in bookshops; they go there with relatives, meet friends in them and treat them like well-known tourist attractions, taking the usual kinds of photos."

Zhang is skeptical about the chances of unstaffed bookshops, because one of the things that 24-hour bookshops have going for them in the relentless battle against online bookselling is that they bring people together, he says.

"If you ask me, bookshops with no people seem a bit vulnerable."