I have a Tumblr, but I despise the site. It's not a site for artists posting art IMHO :( IT's actually made me HEAVILY depressed over 2013 to the point where I barely drew while I was having a super stressful time in my life with moving. I don't know if it was made worse, or if it caused a lot of my stress, but it's not a healthy site for me, and I'm trying to pull away. It's really targeting information sharing which doesn't lean towards a personal experience. I REALLY hate that I can spend 10 hours on a picture and get 20 likes / reblogs, while a doodle of the same fandom will get 250 or more. IT's so heavily face value.
I'm on Tumblr though. Even if I do manage to pull away, I'll post art there, but I do it begrudgingly.