I've had an account since 2008, but art publicity isn't a priority of mine. Until recently, I would only show my work on Facebook. Going into public education - graduating May 2013 - I've found my 'portfolio' is hindered due to Facebook commonly being blocked on school-district internet due to the social networking.
dA is just a work-around; don't expect much, ha.
Also, many of my early drawings are unoriginal - they were for 'educational use' and demonstrate a progression of skill. I now rarely draw photos I have not taken, with the exception if it is done with permission, commissioned, or a public figure.