Yes, you can get your back dimples pierced. It is another form of piercing that is being seen of late. If you would like to view the process, check www.youtube.com/watch?v=3nSCr-hotpc. They have a step by step video on the procedure.
Go to a piercer that does microdermal piercings, depending what state you live in it might be difficult to find a tattoo/piercing studio that is credible. I researched getting them done for almost a year before I got them. But no worries they don't hurt as bad as it looks!!