It is possible to use free professionnal fonts, with a commercial use licence.
How to find free fonts & webfonts With commercial licence
Here are the websites where you can download free fonts and receive email alerts about new fonts. Most of those fonts are given with a commercial use licence. So you are free to use it for business purposes!
And of course, if you need to use a webfont, there are dedicated websites :
This post will be updated regularly. If you have suggetions, please post them in the comments! Those might be added after I check them out.