I like that you can use it anywhere! You don't need an office phone system or even internet access just because someone is in another part of the world.
We have used this software when we needed to communicate while out at our facility (in other states). It was easy enough to set up but not so user friendly if they weren't familiar yet could be improved upon. The customer service has been amazing as well!! They are always willing to help us figure things out without being pushy about taking over my computer screen etc..