I'm considering making an alt-chan that cyclically purges content.

By now, it should be obvious that your efforts to attenuate the duration of long-running content won't prove to cultivate an increase in the quality of participation.

There are (at least) three aspects of online community participation, that seasoned users are pretty well-versed in:

  1. Archiving, mirroring and back-ups.

  2. Leaked screen captures and scrapes 
     of private direct messaging.

  3. Back-end aggregation of logs and 
     messages, even for supposedly private 
     SMS interactions.

Forget it dude. We all know that whatever signals get placed onto the wire turn out to be spliced through passive beam splitters and land in an open S3 bucket.

The ones that don't? Your girlfriend just screenshots it, and and tweets it out in the open for the world to see anyway. Whoops!

There are no more online subcultures. Only distortions of perception enforced by impulsive, would-be moderators.

The point of imageboard-style thread pruning isn't to erase the content from the Internet (after all, there's a small archive for every board on 4chan on 4chan itself and much larger ones elsewhere on the net) but rather it's to keep the content fresh and encourage new material rather than ruminating on old material - it's much easier to notice new posts when threads are small, instead of scrolling through 1000 posts that most people never bother to read. HN deals with it with the fact that if you comment on a HN post two weeks after it was posted then it won't bump the thread.

There is still one place left on the internet where conversations more or less fade away forever after they end: IRC

Sure, there are probably logs somewhere. User logs and server logs. But in all the decades I've been using IRC, I've never seen my chatlogs show up on a search engine before. It's just obscure enough and just low value enough to slip under the radar.

What about bash.org?

Oooh, If you're still at the stage of getting ideas for what people want to see...

Merchandising. I'd love to support a site like that with mugs or shirts of my favourite greentexts. You could get memorabilia of the instant when memes were born, and it would fix the monetization problem that pops up when they get big.

> You could get memorabilia of the instant when memes were born

An irrational anger stirs deep within my soul at this suggestion. Too many marketing agencies have attempted to monetize internet culture with catastrophically misguided results. At this point, monetizing internet culture is synonymous with meme murder.

Curious how you think this is a solution? There is often really useful info hidden in old threads, why would you purge that?