J.L.W.S. The Special One wrote:
If I were a professional photographer or artist, and I released my work under a free license, I wouldn't be able to earn a living.
If you put a free license on some of your photos and 145889 people downloaded and shared it, you would have 145889 people knowing about you, and knowing that you make great photos -> they may hire you.
Note that: a) We're not saying you should publich *all* your work. If you have 20 photos of John Doe, you can publish one low-quality and sell the other 19.
b) People copying your photos will get even less profit, as they will have to acknowledge you were the author (i assume at least a Attribution License).
c) If your work is bad. There's very little licenses can do to make you earn more money.