The "crossing" or exchanging of books may take any of a number of forms, including wild-releasing books in public, direct swaps with other members of the websites, or "book rings" in which books travel in a set order to participants who want to read a certain book. The community aspect of BookCrossing.com has grown and expanded in ways that were not expected at the outset, in the form of blog or forum discussions, mailing lists and annual conventions throughout the world.
Leaving reading materials in public places when no longer needed has long been a silent means of communication and sociability amongst bibliophiles. Ron Hornbaker conceived the idea for what is now known as BookCrossing in March 2001 and enlisted business partners and co-founders Bruce and Heather Pedersen to launch BookCrossing.com on April 21, 2001.
After two years the website had over 113,000 members and by 2004 it was prominent enough to be referenced in an episode of the Australian soap opera Neighbours. The same year it appeared as a new word in the Concise Oxford Dictionary, although as of 2017 only Collins of the major online dictionaries retained it as a word. Membership surpassed 1,000,000 by March 2012 and the registered book count exceeded 8,500,000. By 2017, there were over 1.7 million members and over 11.7 million books travelling through 132 countries.
In July 2007 Singapore became the first country to give the practice official status, designating 2,000 locations in the country as 'hotspots', similar to Official BookCrossing Zones, in an initiative launched with the National Library of Singapore. The world's first official International BookCrossing Day took place on 21 April 2014.
In May 2005 BookCrossing.com won two People's Voice awards in the Webby Awards for best community website and best social/networking website. BookCrossing was also featured in a BBC Radio project broadcast as 84 Book Crossing Road, which involved releasing 84 copies of Helene Hanff's book 84 Charing Cross Road around the world. The programme was nominated for a Sony Radio Academy Award in 2006.