The document delivery service of reading show is a fee-based service. According to official website, a reading show, the library resource reference and consultation center provides document delivery service, which sends the information needed by readers to their mailboxes and provides full-text reading. The consultation volume of each book is limited to 50 pages or 20% of the whole book (whichever is smaller), and all consultation contents are valid for 20 days. Restrictions and service details indicate the charging nature of the service.