Comfortaa is free for personal/noncommercial use, AND commercial use.

Comfortaa is licensed under the SIL Open Font License, Version 1.1.
http://scripts.sil.org/OFL
This is the standard license of open source fonts and has very few restrictions. Read the "OFL - Font License" file included in the Comfortaa folder for detailed information on the license.

If you still have questions or comments, you are very welcome to write to my email: aajohan@gmail.com