The article does kind of define it, but does a poor job.

An emotionally sticky node is a user who makes other users stay on the site. Examples of this for Reddit would be accounts like poem_for_your_sprog, ShittyWatercolor, Shittymorph, or wil.

There are others, of course, that you may not be able to name - /r/California was mostly kept alive by /u/BlankVerse, who posted 85% of all the articles to that subreddit. You’d never notice unless you paid attention to usernames. Similarly, a small percentage of people made a large percentage of Reddit’s OC. Typically you couldn’t name them, either, but you’d know if they weren’t there because they gave Reddit a soul.

Reddit started off as a bunch of bots reposting links they found, without even a comment section. Eventually real people came and started posting nerd stuff (like programming articles) alongside the bots. Enough of a critical mass was created that a comment section was added, making old Reddit look like what HackerNews or Tildes look like today. The programming and porn were sent to different subsections of the site for the people who don’t want to see such things (these became the first subreddits). The default subreddits were slowly created, then anyone could make their own subreddits for their own topics.

Still, it was largely posts to things found elsewhere. People went to Reddit as part of their trip through several other websites. They’d usually gather what they found during that trip and repost it to Reddit. OC wasn’t expected; reposts were encouraged. By the early 2010s, a lot of the pictures on Reddit were mainly 4chan reposts. People who had a lot of stuff saved from other sites were the “emotionally sticky nodes” and people would come to Reddit to see stuff that was explicitly gathered from everywhere else - hence why Reddit was the “frontpage of the internet”, an aggregate of what people had found elsewhere.

Eventually we started to see OC for the first time. Advice Animals sprung from 4chan memes and really started to go viral across Reddit. Reddit users started making their own native advice animal formats and now Reddit was no longer just “things from elsewhere on the internet” but new content you couldn’t see elsewhere. Soon these people making OC became the “emotionally sticky nodes”, keeping users on the site.

And, of course, there are other things who were “emotionally sticky” without necessarily posting memes. Reddit became a great place to aggregate news at-a-glance. This is because of the moderation of the news and politics subreddits, ensuring that things posted to their subs were actual articles, post names were real headlines (no editorializing!), and the page wasn’t littered with random YouTube videos or self-posts or images or whatever. Good moderation meant that you could go to /r/news or /r/worldnews and trust that you were getting the same effect as looking at the headlines of a newspaper. Similarly, the 2012 election had /r/politics become a great source of information and discussion about the US Presidental Race. These sorts of things made Reddit a useful site and kept people coming back.

Even now, Reddit still has “emotionally sticky” places. They could be individual users like the ones I mentioned above, or they could be entire subreddits that aren’t quite captured here on Lemmy/Kbin yet. Neither Lemmy nor Kbin have great mod tools, and a lot of mod teams here are inexperienced and not as aggressive as Reddit mod teams are. You can argue this is a good thing, but aggressive moderation really matters for places like the news communities where legitimacy comes from users avoiding editorializing. This means that these places aren’t a good replacement for Reddit (yet) - subreddits where moderation is important are still “emotionally sticky” because nothing can compete with them. (This is why it’s important that Lemmy develop good mod teams and good mod tools!)

There are oodles of niche communities that you’ve never heard of that haven’t come over, either - for example, !modeltrains (@modeltrains) and !nscalemodeltrains are niche communities on Reddit, but neither of their fediverse counterparts have much activity (other than me). People on Reddit thus don’t want to leave their niche community because it doesn’t have any activity over here, and because there’s no activity over here, nobody wants to come over here to start activity - meaning there’s no activity over here. That’s why it’s important to make sure you contribute often to niche communities you care about, even if your content isn’t “good” - there needs to be something to lure emotionally sticky nodes here and get people to jump over.

That said, some places absolutely have made the jump successfully (!196). But for most places there’s a while to go before Reddit gets to the point where it can’t maintain itself as a site.