That'd require finding people on Tumblr you'd like to talk with - and the format of Tumblr is such that you just don't know if you want to talk to them on Skype when you can hardly talk to them in brief comments. Also, to be interested in talking to people requires genuine interest, which'd usually involve yourself and those people willing to blog stuff that's not fandom stuff or reblogs, talk about personal life at a place that is fully public. Which... urgh.