Posts with images are more attractive to the human eye. They are more likely to be shared and liked. Every article, blog post, Facebook post, even Tweet is better with at least one image. Images also serve to help break up long bits of text and move the eye down the page. Done well, images can even help your marketing by catching the eye and providing a favorable impression.
Images can even be their own content, as the success of sites like Instagram and Flickr can attest. Images can capture interesting events, share feelings, and bring us closer to each other. The success of all the funny cat photos/videos on the internet shows just how much people like good/funny photos.
Besides using your own images, which is a great idea if you have quality photos, there are also paid sites like istockphoto and shutterstock. Or sites that let you search for free photos — ones with creative commons licensing are best. Remember that just because a photo is posted on the Internet does not mean that it is free to use. Copyright holders have been known to go after people who use their photos (and content) illegally, which can cost thousands of dollars.
If you’re using WordPress, Zemanta offers a nice plugin that searches for relative free-use images and has an interface to let you add them to your posts.
How do you use images in your posts?