Every list seems to go through the same cycle:

1. Initial enthusiasm (people introduce themselves, and gush alot about how wonderful it is to find kindred souls).
2. Evangelism (people moan about how few folks are posting to the list, and brainstorm recruitment strategies).
3. Growth (more and more people join, more and more lengthy threads develop, occasional off-topic threads pop up).
4. Community (lots of threads, some more relevant than others; lots of information and advice is exchanged; experts help other experts as well as less experienced colleagues; friendships develop; people tease each other; newcomers are welcomed with generosity and patience; everyone -- newbie and expert alike -- feels comfortable asking questions, suggesting answers, and sharing opinions).
5. Discomfort with diversity (the number of messages increases dramatically; not every thread is fascinating to every reader; people start complaining about the signal-to-noise ratio; person 1 threatens to quit if other people don't limit discussion to person 1's pet topic; person 2 agrees with person 1; person 3 tells 1 & 2 to lighten up; more bandwidth is wasted complaining about off-topic threads than is used for the threads themselves; everyone gets annoyed).

an 'old' question or responds with humor to a serious post; newbies are rebuffed; traffic drops to a doze-producing level of a few minor issues; all interesting discussions happen by private email and are limited to a few participants; the purists spend lots of time self-righteously congratulating each other on keeping off-topic threads off the list).

6b. Maturity (a few people quit in a huff; the rest of the participants

stay near stage 4, with stage 5 popping up briefly every few weeks; many people wear out their second or third 'delete' key, but the list lives contentedly ever after).