[nostrademons]

This is more true of communities built around ideas rather than activities, and there are also moderating tactics you can use to avoid it. For example, online communities based around astronomy, or radio-controlled airplanes, or baking, or other hobbies remain relatively healthy even decades after their founding.

Also there are communities around conventionally caustic topics (eg. Lambda: The Ultimate for programming language design, Penny Arcade for games) that manage to survive for a decade+ with no loss of quality because of moderation policies. For example, L:tU has an "avoiding ungrounded discussion" policy - every thread must be centered around discussion of a published academic paper, which first of all keeps the focus on people who actually do work, and second of all discourages everyone without the background to read and understand academic papers.

[jballanc]

I don't understand how people constantly miss the most obvious solution to keeping a community grounded: charge an entry fee.

[bbaumgar]

Could you point to some examples where this has worked? It seems that the entry fee would either 1. limit the community's growth severely (not necessarily a bad thing), or 2. filter out good candidates.

[rfrank]

SomethingAwful's forums required a paid membership and have been around a long time. IMO one of the points of a paid model is keeping membership down to people who actually care enough to pay said membership.

[alexandersingh]

Additionally, the implicit threat of having your paid membership revoked for bad behavior can provide a natural check.

Something Awful has used this to great effect to keep trolls in line. I wonder what % of their membership revenue comes from banned users purchasing new accounts.

[zemvpferreira]

I'd say most of it, at this point. As a long-time goon, getting banned and rereging the account is a way of patronage. No joke, it's very common behaviour there.

[shrikant]

In addition to the examples posted, this model also worked well for MetaFilter. Some of the highest quality online discussions I've seen.

[stevewilhelm]

TED and ACM

https://www.ted.com/ http://www.acm.org/

[pc86]

ACM is a professional association, and I wouldn't consider TED a community.

Neither of these is anything close to a subreddit or forum which is the "community" to which the thread is generally referring.

[Spivak]

I would think that LWN is a good example.

[MarcBodnick]

What are examples where this has worked? MetaFilter is one, but very small.

[xiaoma]

That doesn't work at all. Just look at sponsored posts on pretty much any publication/blog/forum. Every single one is paid and they race for the lowest tolerated behavior.

[bjelkeman-again]

Good moderation works well IMHO.