When ongoing worthwhile conversation appears on a small board, the S/N ratio goes very high fast. Word spreads, and people are attracted to a high-interest low-

When ongoing worthwhile conversation appears on a small board, the S/N ratio goes very high fast. Word spreads, and people are attracted to a high-interest low-noise signal. As more people join in, everyone can be heard ... but not everyone should be heard. The growing noise starts drowning out the signal, which gets frustrated and heads for less noisy grounds. The sheer mass & momentum of the noise sources keeps the place going for a while, but more "signals" leave over time, leaving a shrinking population. Various mechanisms are put in place to suppress noise, with varying degrees of success (HN's is pretty good). "Freshness" is also a factor. After a while, each forum just starts showing its age, not keeping up with spiffy new forms & forums. People get bored and move on. "Us vs them" is also a factor. A growing subgroup may decide they just don't want to be around the base. Prime example: Facebook and the alleged "kids don't use it because their parents are there". Embrace the lifecycle. It's real; instead of fighting it, manage it with the understanding that it will eventually fade and users head to newer quieter forums.