What does one do on Tumblr? Is it fun? Should I get one? I've been there but it still confuses me.
Get one. You reblog and post a bunch of stuff, talk to people, ask them stuff, and...yeah, that's pretty much it. Oh, and there's porn.
tumblr is awesome, especially to follow the fandoms you like. XD
I guarantee you'll come across some great, hilarious stuff if you join.