I do not understand Tumblr RP either. It seems sort of like Gaia/avatar forum RP in that it's based around "how long your post is = quality" except it's also sort of like journal RP in that a lot of it is fandom-based or people will like post scenarios and fancast actors to play the specific roles they need? I had a guide somewhere.
no subject
I think I like this better though. X3