[2] The Street Performer Protocol is a natural extension of the much older idea of funding the production of written or creative works through agreements between groups of potential readers or users.
Unlike today's meaning of subscription, this meant that a fixed number of people had to sign up and pay some amount before the concert could take place or the printing press started.
The most important difference is that traditionally, the subscribers would be among the first to get access and would do so with the understanding that the work would likely always be a "rare" good; thus, there was some status in owning a copy, as well as the prestige of being among the patrons.
In the modern Street Performer Protocol, each funder chooses the amount they want to pay, and the work is released to the public and freely reproduced.
The newly created Blender Foundation campaigned for donations to obtain the right to release the software as free and open source under the GNU General Public License.
SPP is the threshold pledge system encouraging the creation of creative works in the public domain or copylefted, described by Steven Schear[7] and separately by cryptographers John Kelsey and Bruce Schneier.
[2] This assumes that current forms of copyright and business models of the creative industries will become increasingly inefficient or unworkable in the future, because of the ease of copying and distribution of digital information.