On the surface, the GNU/Linux project and FreeBSD are both considered “open source” software which implies “free” to use. In fact there is a lesser-known clause in the Gnu GPL that might be of interest to entrepreneurs and developers:
“Linux is available under the GNU General Public License (GPL), which is designed to eliminate closed source software. In particular, any derivative work of a product released under the GPL must also be supplied with source code if requested. By contrast, the BSD license is less restrictive: binary-only distributions are allowed. This is particularly attractive for embedded applications.”
This technically means if you use any GPL code, you may be asked to give up your own source code to your own work that integrates a GPL project, if requested. This provides a clear legal, business reason for choosing FreeBSD over a generic flavor of Linux.
For more specifics on the differences between GNU/Linux and FreeBSD, check out the following links:
https://www.freebsd.org/doc/en/articles/explaining-bsd/comparing-bsd-and-linux.html
https://www.reddit.com/r/sysadmin/comments/3odphp/why_do_you_love_freebsd/