My daughter is a professional photographer, and is always reading up on the latest things, trends, etc. She set up a FaceBook page after reading from a famous photographer that he had spent $900 to advertise for senior portraits and got 3 responses. He started a free FaceBook page, and got something like 100 responses!
FaceBook expands your contacts. I set you up as my friend, then all my friends see that I am friends with you, and they can make you their friend. Then, their friends can see they are friends with you, and they will know about you too! It is sort of a pyramid.
If you are concerned about it taking up too much time, or that you will have to wade through all the non business chit chat, you can make someone a friend, then hide them on your page (they don't know), or hide when they play a game, etc. You will receive an email notifying you when someone specifically is writing to you.
Also, when someone compliments your work, it is there for all to see (and if by chance someone says something bad - you can delete it!)