iStock is an online, royalty free, international micro stock photography provider. The firm offers millions of photos, illustrations, clip art, videos and audio tracks. Images cost between 1 and 3 credits, with the price of credits ranging from $10.00 to $0.22 depending on volume purchased and subscription plan. ). Artists, designers and photographers worldwide contribute their work to iStock collections in return for royalties. Nearly half a million new photos, illustrations, videos and audio files, are added each month.