Dear (use first name),
I am writing today to encourage you to promote free software in your communications with the general public and the IT industry. Free software as defined by the Free Software Foundation is software you can run for any purpose, modify to suit your needs, distribute copies of legally, and finally for which you can distribute your modified copies.
With the removal of licensing restrictions against use, copying, and modification of software, each of us can spend our time more productively. Being able to modify software and view its source code means when a bug is found or a new feature desired, we are free to fix or extend the program ourselves or to hire someone qualified for the job.
Many companies are today trying out free software, using it for their core business functions, or are building entire new businesses and ecosystems based on free software. Examples of free software include the web browser GNU Icecat(based on the non-free Mozilla Firefox), OpenOffice.org, and GNU/Linux distributions like Kongoni and gNewSense.
If you'd like to learn more about free software and its benefits, I implore you to try out gNewSense, Kongoni, or OpenOffice.org. If you prefer to read about free software, please visit http://fsf.org, http://openoffice.org, or http://trygnulinux.com.
Thank you for your thoughtful consideration of free software and it's benefits to companies, computer users, and people everywhere.
Sincerely,
(Your name here) (feel free to add anything you like to your letter, a list of free software you use and for how long, your position and title, or maybe how much you've spent guided by your interest in free software)

If you would like to encourage more work in this vein, donate Bitcoins to: 1PycTeyJBiA2XKXURykamcvSrrcY81yTXG