Answers.com used to make enough ad revenue from their copies of Wikipedia pages that they sponsored Wikimania with it. And of course Cygnus, Soft Landing Software, Slackware, Red Hat, CheapBytes, and so on, have made a great deal of money on GPL software, most of which they didn't write themselves.

It's true that CC-BY-SA doesn't include the source-code-provision provision of the GPL, because it isn't intended for software, and it isn't clear what the source code for, say, a photograph would be. A PSD, maybe; but what about the RAW from your camera? What if you don't shoot raw? Are you obligated to include documentation of the photographer's lighting setup in order to redistribute? Their thinking about the framing? Shots from the other angles they tried that didn't work out? Such considerations would probably have resulted in SA works being impossible to legally redistribute in practice, so the license doesn't impose them.