If you are publishing digital content to the web, an easy way to encourage people to share and distribute your work to reach a broader audience is a Creative Commons license. Providing a level of protection somewhere between a full copyright and public domain, CC actively encourages people to spread your content around in a way that would be impossible otherwise.
In essence, a Creative Commons license allows people to use your content as long as it is used and credited in a specific way, so that it is still clear who the original author is, but people can use, remix, and distribute the content without fear of legal action. The truth is that obscurity is a far greater threat in web marketing than piracy. Anything that increases your profile will ultimately result in sales, but if you don’t let your content out, you can’t gain an audience.
The truth is, people are going to reuse your content whether you like it or not, so a CC license increases the likelihood that you will be credited, linked, etc… Many influential bloggers are careful not to infringe on copyrights for fear of lawsuits. Make it easy for the people you actually want linking to you, those with credible reputations, to do so and you can be assured you will be credited and reach a wider audience in the process.