This is why I decided to be on tumblr!
Please take a look at the above Alexa rank. The traffic rank for tumblr.com is the 21st in US, and 36 in the world. The features less then blogspot, but of course richer than twitter.
So let see how it goes.
Update on 19 Nov 2012: I opt out from tumblr since Aug 15, 2012 due to some reasons. I then redirected all the feed to my tumblr account. And for that my tumblr.com account has been suspended indefinitely. I'm not complaining, No sweat!