Images are, of course, useful for any website, social media, or e-mail marketing project. But it’s not always feasible, as a result of time and budget constraints, to produce original images. And copyrighted images are costly. Try the public domain first and see what you find. You may be surprised. Here are some good places to begin your search for high-quality public domain images:
Flickr Creative Commons (this page also provides a good explanation of Creative Commons licenses)