Whitman called his venture "a socialist utopia masquerading as a bookstore". Henry Miller called it "a wonderland of books." The shop has beds tucked among the shelves of books where aspiring writers are invited to sleep for free in exchange for helping around the bookshop, agreeing to read a book a day, and writing a one-page autobiography for the shop's archives. These guests are called "Tumbleweeds," after the plants that "blow in and out on the winds of chance," as Whitman described. An estimated 30,000 people have stayed at the shop since it opened in 1951.