The payment IS a social interaction. It's the companies who pay for job posts paying you to see have access to their job posts. It's also a primary incentivizer for people who do nothing but "like" stuff to keep liking things and coming back. It drives user behavior. It's unlike other social media, where use behavior is driven by other users liking their stuff, and then the service is free in exchange for access to your subconscious through ads. Here you can see what the value of your subconscious is. That said, it's hardly subconscious at this point, since people here already have pretty much accepted Bitcoin into their life, and there is only Bitcoin related stuff. But give it 20 years with the existing model and I see this sort of being the elevator pitch.

Related, this is a "social media" site. But, social is such a funny word. There's a great bit in Hayek's 'The Fatal Conceit' about the word that I really love. The book in PDF form is here. The passage I'm talking about starts around page 110 titled 'Terminological Ambiguity and Distinctions among Systems of Coordination'.