I often license my fine art work to various magazines and publishers. Recently, I was asked to license an image from my newest series FOG for a German magazine Der Spiegel. They had an article about dreams and they found my website and contacted me to supply the art for the article.
I few years back, a UK based magazine called New Scientist found my work through the stock site Corbis Images. They were also running an article on sleep and dreams. Their editors found one image they liked on Corbis, but wanted a few more to round out the article.
This is the image that they bought from Corbis Images: 
Then they licensed these two directly from me and ended up using one of them for the cover as well! The cover image is an additional use of the image and warranted a larger licensing fee.
I have also worked with a few publishers for book covers. I have shot a few covers, but some publishers find it easier to license pre-existing work for their smaller run publications. I was contacted by Actes Sud, a French publication, to license an image for a book cover. They ended up licensing the same image that the New Scientist used for their article. Since they are different mediums (magazines and books) and in different regions (UK and France), I was able to license it twice. Also, both licenses were non-exclusive.
With Held Breath 