Royalty free means you just need to pay for the item once per end product. You don’t need to continue to pay based on the number of people who see or use it. Please note that there are limits on the number of times you can use an item under our PhotoDune licenses (see PhotoDune FAQs for more information).
Example: If you license a brochure template and create a printed brochure given out for free, you don't need to pay based on the number of copies of the brochure you make. If you use a 3d model in a game under an extended license, you don't need pay based on the number of times the game is sold.