Sharing and the gift economy
Carol and I decided to license the recipes on our new healthy foods and recipes web portal under a Creative Commons license that allows people to re-publish our stuff with attribution and a reference to our web site. For us, this makes sense: we want people to use our web portal and sharing recipes is one way to promote it.
I do the same thing with my free web books and open source software projects: by sharing I get good feedback and improvements from many people and because hundreds of other web sites reference my main web site, when anyone searches for a "Java consultant", there I am :-)
I frequently push back a little with some of my customers who want to keep everything they do closed and proprietary. Unless you are helping a competitor put you out of business, sharing has many rewards.