So it's not just the cost of setting up/running a server (which people tell me here could be quite minimal). It's the man-hours of prep, setup, and ongoing maintenance for things like moderation, tech support, etc. that come into the equation.
And the other half of that equation is the assessment the people involved make of the opportunity. Math is a big part of that. How many users are on that network, and how many of those people are likely to see or engage? 2/2