I think there was a platform several years ago - maybe App.Net - that tried this but had to eventually close. Perhaps the climate nowadays might be more suited

I think there was a platform several years ago - maybe App.Net - that tried this but had to eventually close. Perhaps the climate nowadays might be more suited to support a pay model? Small though it might be, I'm sure there would be a portion of the population that would pay for this. The trick is in the marketing and in triggering the network effect.