Reddit really 'dug' (see what I did there) its own grave by aggressively catering to casual users, in order to drive signups and grow the user base. I can't remember exactly what happened at which point, but it all follows the general pattern of appealing to the mass market. E.g. the curation of the frontpage via default subs such as /r/AdviceAnimals that don't really contain meaningful discussion. There's no real need to do this if one is concerned with maintaining an existing community, or the standards of it. As a counterexample, private trackers have been rather good at this, generally by having interviews/invitations for new memberships, or even disabling signups entire. Though these are really the most extreme options.

The other main problem is that like Digg, that there is a powerful cabal of moderators in control of most mainstream subreddits, including those concerned with serious topics like news and politics and they do a lot of "curation" of content by removing stuff, rather than letting the users decide on which links and topics are relevant to discussion (by, ya know... upvoting/downvoting) with chilling effects on those respective subs. That this was allowed to continue, without overhauling and maybe even democratising the moderation system of default subs, was Reddit's choice. I can only suspect that this either (a) plays into the hands of advertisers directly via corporate censorship or (b) indirectly, by relegating content from users who fall outside of the "mass-market" demographic to niche subreddits or other websites.

Curation of shitty content is also built right into the algorithm.

They'll hide behind "But people are voting for this mindless content" but that's not the full picture. A vote after 5 seconds is actually weighted higher than a vote after 5 minutes.

It's specifically because Reddit the company is against too much engaging content. They want people to smirk, chuckle, acknowledge, and move on. Engaging content means fewer pages viewed, which means fewer ad views.

A vote after 5 seconds is weighted, or acts as if weighted?

If that's built into the algorithm, that's one thing. If the social effect of early moderation is amplified, well, that's still a problem (and a major one), but ... of a different sort.

Citations requested.

The first graph linked below shows "hotness" as a function of time with upvotes held constant. The equations are above the linked section. Compounding this effect, there is a feedback loop where hotter elements are more likely to be seen and voted, which increases hotness logarithmically.

So no, the algorithm doesn't intentionally punish dense material. But it does happen incidentally.

https://medium.com/hacking-and-gonzo/how-reddit-ranking-algo...

Right. Reddit definitely doesn't favour quality.

The name I've heard for this is "Eternal September":

https://en.wikipedia.org/wiki/Eternal_September

Yeah, that was posted elsewhere in the thread. I thought of it as a name specific to Usenet, as Network Decay is specific to television networks. I was hoping for a general term.

I don't think the term is specific to Usenet at all. It's genesis is in Usenet, but I've heard it used many, many times to refer to the general phenomenon that the original Eternal September was a specific instance of.

It's fine to say that, but this phenomenon is even older than the Internet. Think of the hip bar that gains a sudden influx of customers following a New York Times story. Yogi Berra remarked on this phenomenon with one of his famous quotes "Nobody goes there anymore. It's too crowded!"

Another idea related to the general phenomenon is gentrification: the cool artist colony suddenly overwhelmed with yuppies who drive up the rent, forcing the artists to move out.

Is there not a general term for this whole phenomenon?

I call it wankerisation. That is, a place, location or destination has become overwhelmed with wankers.

"I don't go to that bar anymore, it's too wankerised."

"I don't visit Facebook anymore, it's become wankerised."

"The neighbourhood is too wankerised, I can't afford to live there."

For communities and interests, I usually call it simply "getting mainstream", and the invaders "general population".

Eternal September afflicted mailing lists, too.

It happened a lot before Reddit too. Forums always used to have this cycle of starting out appealing to more mature audiences before getting flooded with casual users and spammers and many people then moving elsewhere.

Heck, in the world of webmaster forums, the ease in which they got filled with spammers and low quality content meant that the same people usually ended up being members of dozens of different forums and moving to a new site every month or two.

Other possible factors:

Is the monkeysphere is the root cause of the endless bifurcation of communities, culture? https://en.wikipedia.org/wiki/Dunbar%27s_number

John Dvorak once opined that social networks stop being cool when that coworker you secretly hated tries to connect.

Of course, pushing the other way, is the power law distribution of attention. The best explanation I've read for our current winner takes all economy. http://www.shirky.com/writings/herecomeseverybody/powerlaw_w...

Appeal to the masses. It's a very pervasive concept.

See Hannah Arendt's "The Crisis in Culture" (by way of ... Reddit):

https://www.reddit.com/r/philosophy/comments/50umjw/hannah_a...

http://www.celinecondorelli.edu/files/arendtcrisisinculture_...

There's the "evaporative cooling effect":

http://web.archive.org/web/20101012105003/http://blog.bumble...

I see these as mechanisms based on Gresham's Law, though that's based on a longer argument.

I believe "cool kids" is primarily used as sarcasm.