[dimva]

You pay for services where there isn't a network effect (streaming) or where the market isn't super competitive (telecom). Social is an incredibly competitive market with a huge network effect - if Facebook or Twitter charged money, young users would migrate somewhere else and would continue using that network when they got older. So that would be the end of any social network that decided to charge, unless it was trying to be a small niche network for adults to have more intellectual conversations (metafilter?)