I would definitely agree that IM clients are not a perfect analogy to social networks, and I only used them as an example because they've been around longer tha

I would definitely agree that IM clients are not a perfect analogy to social networks, and I only used them as an example because they've been around longer than 'modern' social networking apps/websites. I agree that Facebook could theoretically be a natural monopoly, but in practice there appear to be many social networks operating in parallel. This may be an unstable equilibrium, but I view LinkedIn, Instagram (before the takeover), and to a lesser extent TikTok, SnapChat, Reddit, Youtube, and Twitter as Facebook competitors. It seems like there are many people who use more these networks in parallel, which means that there is no natural monopoly. On the other hand, I do believe that Facebook has a so-called 'moat', though it may not be as strong as some others believe.