Once you've been a member of a forum for a period of time, you start to notice the repetitive nature of threads, restatement of entrenched points of view and the generally bounded nature of the discussions relating to the core topic. From this point there tends to a progressive disengagement from the community and your interest level starts to drop off.
I think it's normal that a lot of forum users will go through a cycle of discovery, enthusiastic engagement and involvement, a plateau of interest and then progressive reduction in participation. For a lot of people who join a forum, there is a transactional nature to their participation - they have a problem or need questions answered and once the itch has been scratched they tend to fade away.
That's why there is a certain churn of active membership that goes together with a hard core of committed participants that enjoy being members of a virtual community on a long term basis. So it's just a hypothesis, but if less people are joining a forum because interest in Hi-Fi as a hobby is waning (as opposed to interest in music in general) do Hi-Fi fora experience a reduction in membership growth? it would be interesting to know what the trends are in new member signups, volume of posts per user and what the profile of volume of posts looked like over time.
For myself, as my sig shows, I haven't bought any new Hi-Fi stuff for a couple of years so I have less to tell you all about, certainly little that is novel or hasn't already been covered in depth by others. I still check in periodically but am certainly less active than I once was.
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