Promote your site on Facebook, Twitter, Google+ and Linkedin. This is the best way to advertise.
Create a blog and showcase your work. Connect with other bloggers and people in social media. Collect emails so you can further get in touch with them. Spread the word everywhere in a none spammy manner. More importantly, PROVIDE value to readers.
You have to self advertise on the Internet everywhere you can... Kind of like what your doing now 0_0
STEALTH ADVERTISEMENT?!
SEO and SMO is best way to advertise your art website
How to advertise my art site http://dimis.artistwebsites.com/index.html
