These images were not taken very seriously in the design world and usually ended up just being sold for use in textbooks and such. But this practice has changed considerably and today most stock photography houses offer both traditional stock images and royalty-free images. Stock work is usually cheaper than custom assignments because photo-buyers are required to pay only a rental fee based on the size, distribution, and exclusivity of the images used. Tight publishing deadlines have become easier to meet because stock images are readily available. And stock agencies categorize their images in according to subject matter reducing even research time.
Stock photography requires a simple contract that is usually based on usage and size specifications.
This can reduce the design approval process, by enabling images to be approved for use prior to their purchase. Royalty-free companies generally pay their photographers a flat rate for their work. That's why it is often possible to buy a CD filled with royalty-free stock photos for less than the price of a few traditional stock images. However, if you require unique and arresting images, you will most likely shop at traditional stock houses. It is possible that the picture you purchase from a royalty-free company for your company's brochure, is also being used by another company.