But isn't Tumblr userbase mainly teens and their subcultures? What's the value of not having ads, sponsor and astroturfing, if there's not relevant or interesting community to join to begin with?
I wouldn’t say there’s nothing interesting on tumblr.
Like, there’s nostalgebraist’s writing on machine learning, Also other people posting some math content.
It is a social blogging site. People write blogs there.