And I don't think the premium membership affected page views all that much.
If it did I didn't notice, but page views seem to be directly connected to a few things. Gallery uploads, spread 'em out because each one gets you views from other DA members. Group memberships which also gets you a lot of internal views. But it's just increasing the pageviews of stuff you've already posted, by posting them to group pages. Outside promotion, things like mentions on twitter or someone posts your stuff on their blog with a link back to your DA page. And quantity seems to help to, the more stuff you have the more people come back.
There seems to be two distinct groups there. Pros and kids. People who consider themselves artists, professional, semi-professional, hobbyists, all really good artists, and rest seems to be a pretty large community of "fans." Who are there for fun.
It's like a hotel booking a business conference during Spring Break. So it leads to some really interesting interactions sometimes.
What the premium membership does do, is gives you access to more statistics, which may or may not be useful, but the big difference for me was it gave me a lot more functionality. The free membership has a lot of restrictions and limitations with your page layout.