@_jv_ I think the active users are willing to pay. In my feed alone, a lot of them bought all those username badges made available by Tumblr, even the variations. I was actually surprised there is much love about those badges.
Of course, the situation is more likely different if we consider the entire user base, after all, I'm only seeing the accounts I'm following and are reshared.
Still, if people are willing to buy those badges, they probably are willing to pay some premium.