I don't think this is quite correct. The law is complicated and varies by location, but my understanding (google 'danheller model-release-primer' - can't post the URL) is that model releases are required for commercial publication, and the requirement is for the publisher, not the photographer. The photographer is free to sell the photograph to whomever, but if it's published commercially, the publisher would need to get model releases. So the photographer can take a photograph, put it on her website, hang it in her gallery, sell prints made from the photograph, and even sell it to a newspaper for publication (journalism exemption) all without a model release. But, for instance, Comme Il Faut can't use the photograph to advertise without one.