iStockphoto has announced that it will add royalty-free audio tracks to its collection of downloadable stock content in September 2008. The company says that it will become the first to offer stock imagery, video footage, vector illustrations, Flash files and audio for purchase using one payment model.

iStockphoto is currently looking for composers, performers, musicians and audio technicians to submit music, spoken word/voice, instrumental, ambient and sound-effect audio track submissions. The iStock user community of more than three million members will be able to purchase audio tracks for one to 25 credits each depending on complexity and can be used in Web site production or to complement video footage and presentations. Every time an audio track is downloaded, 20–40 per cent of the revenue will go to the contributing sound artist.

This business model, known as micropayment, was created by iStockphoto in 2001. It not only fueled the tremendous growth of the company, but has also proven itself to be a great way to provide supplementary and sometimes full-time income for contributing artists. In 2007, the company paid more than $20 million in royalties to its contributors.

Sound artist applicants can review a tutorial and take a brief quiz. The artists will then be asked to submit three 5–30 second audio tracks for review and approval. Once accepted as artists, contributors may submit tracks that range from five seconds to four minutes in length. All tracks will be individually reviewed for quality and legality before being approved for sale.

Members of performing rights organisation, (such as SOCAN, ASCAP, and BMI) anywhere in the world are not eligible to submit audio content to iStockphoto, as this precludes the content from being royalty-free. Those who are members of a performing rights organisation can submit content to iStockphoto's sister site, Pump Audio.