[huhtenberg]

It.All.Depends.

It all really depends on what these missing 25% are, on how hard it is to build a minimally viable community, on how big the pool of potential users is, on how exactly you talk to the devs, on where they are located, etc.

Too many factors that could vary wildly and so I doubt that anyone's past experience would be indicative of what you should be doing. In fact if you hear here an anecdote you like it may encourage you to take more risk than you can afford.

[trevelyan]

I think it depends less on the features and more on the competitive landscape. If this guy needs to build a community he needs to rank in Google and get organic traffic. It doesn't matter if he isn't #1 as long as he can get in the top three or four results.

So a single competitor isn't a problem, but if he can't get good positioning because there are other sites he can't dislodge he's facing at best a long crawl to visibility, and is at a huge disadvantage competing against a larger team who already have community, content, ranking, revenues and domain age/trust.