One of the nicest examples used by Andrew Gowers in his report is to be found on page 70, para 4.95:
"Many works that lie unused could create value. For example, the film It’s a Wonderful Life lost money in its first run and was ignored by its original copyright owners. When the owners failed to renew their copyright in 1970, it was broadcast on the Public Broadcasting Service channel in the USA. It is now a family classic, and worth millions in prime time advertising revenue. The book The Secret Garden, since copyright has expired, has been made into a movie, a musical, a cookbook, a CD-ROM version, and two sequels. For works still in copyright, if users are unable to locate and seek permission from owners, this value cannot be generated. For example, documentary makers often find it impossible to track down the rights owners of old pieces of film, many of which have multiple owners, all of whom are untraceable, and are not able to use older works to create new value."