Under the SPP, the artist announces that when he receives a certain amount of money in escrow, he will release a work (book, music, software, etc.) into the public domain. Interested donors make their donations to a publisher, who keeps the donations in escrow, identified by their donors. If the artist releases the work on time, he and the publisher are paid from the escrow fund. If not, the publisher repays the donors, possibly with interest.
The SPP depends on the reputation of the artist, so that he is known for producing valued works and that he will live up to the terms of the agreement. It therefore assumes that the artists will have built up this reputation by releasing works into the public domain, such as previous chapters in a serial.
The publisher may act like a traditional publisher, by soliciting sample works and deciding which ones to support, or it may only serve as an escrow agent and not care about the quality of the works (like a vanity press).
In software, ransomware is a publishing model that applies the SPP to the source code, which is eventually freed under an OSI- or Free Software Foundation-approved license.
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. Mozart and Beethoven, among other composers, used subscriptions to premiere concerts and first print editions of their works. 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.
In 1970, Stephen Breyer argued for the importance of this model in The Uneasy Case for Copyright.
The Street Performer Protocol was successfully used to release the source code and brand name of the Blender 3D animation program. After NaN Technologies BV went bankrupt in 2002, the copyright and trademark rights to Blender went to the newly created NaN Holding BV. The newly created Blender Foundation campaigned for donations to obtain the right to release the software as free and open source software software under the GNU General Public License. NaN Holding BV set the price tag at 100,000 Euros. More than 1,300 users became members and donated more than 50 Euros each, in addition to anonymous users, non-membership individual donations and companies. On October 13, 2002, Blender was released on the Internet as free/open source software.
Several platforms on the Internet allow authors to sell their works using the Street Performer Protocol in a slightly modified way. The threshold pledge system is often used to facilitate the collection of funds.
Variations of the SPP include the Rational Street Performer Protocol and the Wall Street Performer Protocol