For instance, video hosting even 30 second videos becomes prohibitively expensive by basics of storage and bandwidth as soon as more than a few hundred videos are uploaded daily. Setting restrictive data retention policies may negate or standardize some of those costs but you would constantly be smashing into your financial limits with a platform like that.

Further I do not know if enough people would be willing to pay for access to a social media site for it to ever reach millions of users. Even at 1 USD a month per person people wouldn't join in unless millions were already there to make it worthwhile.