Before the 1620s, the only books available in Japan were handwritten manuscripts. The printed "kanazōshi" were less expensive and more widely available than these earlier manuscripts. They are thus considered the first example of commercial literature produced in Japan. One should keep in mind, however, the comparatively limited nature of their popularity. The cost of a single volume was still prohibitive, costing roughly the equivalent of what a laborer could earn for two or three days of work (4000 of Japanese currency). Moreover, the books, because of their small print runs (often only a few hundred copies), rarely circulated beyond Kyoto, Osaka, and Edo, the publishing centers in premodern Japan.