Many people write their own license. This is frowned upon as writing a license that does what you want involves subtle issues. Too often the wording used is either ambiguous or people create conditions that conflict with each other. Writing a license that would hold up in court is even harder. Luckily, there are a number of licenses already written that probably do what you want.
In fact, such a movement exists, and you can be part of it. The free software movement was started in 1983 by computer scientist Richard M. Stallman, when he launched a project called GNU, which stands for “GNU is Not UNIX”, to provide a replacement for the UNIX operating system—a replacement that would respect the freedoms of those using it. Then in 1985, Stallman started the Free Software Foundation, a nonprofit with the mission of advocating and educating on behalf of computer users around the world.
The economic viability of free software has been recognized by large corporations such as IBM, Red Hat, and Sun Microsystems. Many companies whose core business is not in the IT sector choose free software for their Internet information and sales sites, due to the lower initial capital investment and ability to freely customize the application packages. Most companies in the software business include free software in their commercial products if the licenses allow that.
Find popular blogs related to your business niche and read their content. Offer insightful, valuable comments to join the conversation. Make sure you use a Gravatar or fill out the site’s profile information with your first name, last name and photo. You shouldn’t overtly promote your business with this strategy, but it is a great way to get your name out there and network with other industry players.
The best thing about some of these companies is that you don't have to "Like" them on Facebook, send messages on Twitter, or complete surveys. With the companies I've listed first, simply sign in, input your mailing information, and wait for the free sample to show up in your mail). It will take less than 15 minutes sign up and up to six weeks for samples to arrive.