Union Metrics for Tumblr is available today by invitation only, but the companies promise that it will soon be open to the public. In the meantime, you can sign up for an invitation via Union Metrics’ site. (via Tumblr Gets Its First Official Analytics Tool)
I can’t explain to you how excited I am for this. For those of us who are trying to get the studios and labels and networks to put more resources into serving fandom on Tumblr, this is exactly what we need. Thank you, Tumblr and Union Metrics.