If you don't have a tumblr account, don't post.
He asked if someone had tumblr accounts, and what they used it for. Not if you had one or not. a typical +1 post by you. I delete it because it was spam, then you notice that your +1 was gone, and decided to do another +1 to gain back a post.
A few more of your +1 
+1 is when you say something short, meaningless, off-topic just to gain +1 post.