There's a claim going around that Mastodon is "centralizing around a few instances" because 1% of instances account for 84% of users. https://mathstodon.xyz/@manlius/109383027753990134

That's misleading. 1% of instances is ~360. That's a lot more than I expected! Impressively decentralized.

Measuring centralization as a % doesn't make sense. Hypothetically, if 100K new people each started their own instance, centralization as measured by this stat would greatly *increase*, even though that's not what actually happened.

Manlio De Domenico (@[email protected])

Attached: 1 image Again, a quick and dirty analysis, but if I have no bugs then the 1% largest #Mastodon instances accounts for 84% of all users. The top 5% accounts for 97% of all users. We can say that the system is effectively centralizing around a few instances, and this might be a problem for the overall stability and sustainability. @[email protected] @[email protected] @[email protected] @[email protected] @[email protected] @[email protected] #MastoStat #ComplexSystems

Mathstodon

The goal of decentralization shouldn't be a uniform distribution of instance sizes. That's unnecessary and unrealistic.

Decentralization prevents any one entity from exerting too much power over the whole ecosystem, allows cultural differences between communities, and enables semi-independent technical experimentation by instances so that successful innovations can percolate. These are the things that made the web successful. Mastodon has all of these, and isn't in danger of losing them.

One question is about how the current level of (de)centralization will change. I think two divergent paths are possible.

1. Instances continue to be volunteer run (and, in my ideal world, organizations like universities and media outlets will run instances for their members/employees). In this case, decentralization will continue and even increase.

2. There's an influx of commercially run instances. If this happens, there are inevitable centralizing trends — see how Gmail dominates email.

@randomwalker Agreed. There's even a certain 'verified' status to some servers that is probably prized. Like if you are on an official university's server, NASA, huge company etc. that only lets actual employees or members sign up then that's basically like having a blue check.
@randomwalker guess it'll depend on how differentiated the experiences between volunteer-run and commercially-run instances become (assuming that "commercial" refers to instances that seek to acquire new users and profit from running an instance, as opposed to just being an official organization instance) . IMO there's lots of room for a variety of instances as people have different kinds of affiliations they might want — eg geographic region / hobby / professional organization

@randomwalker I think you might have under-analyzed the likely #evolution of the volunteers in world 1. They're going to be confronted with increasing hosting and especially moderation costs, which I think will drive them to professionalize and to make it harder for non-professional instances to federate.

That is, existing commercial entities don't have to adopt #ActivityPub for it to centralize; the volunteers could adapt in centralizing ways too.

@jyasskin @randomwalker
I think that's exactly correct, and part of the problem with any approach that relies so much on the server level for social and technical infrastructure, including moderation and #ActivityPub.

Mastodon and all decentralize globally, but they still centralize to the instance, putting scaling costs there, and now with more inefficiencies from the lack of global coordination.

@randomwalker It happened in XMPP world, Facebook and Google refused to federate w each other and so their chat apps became walled gardens.

@randomwalker I will fight to make 1 come true (and I think we're on the right track).

I honestly don't think commercial instances have a real future. Having a huge instance is costly and aside from crowdfunding there is no real way to monetize.

I also think, as instance "owners", we have to try and promote all the instances and celebrate decentralization, instead of putting ego and numbers before the good of the fediverse.

@randomwalker True! The power law effect will likely appear over time but the fact that anyone can start a new instance to facilitate the exchange of ideas makes it akin to BitTorrent.
@abhi24 But a big instance can refuse to federatewith these new upstarts. It has happened before, to wit XMPP.

@randomwalker it feels like the measure for decentralisation is simply "how big is the biggest instance?" (or top 5 instances).

Another metric would also be how easy it is to move your profile to another instance (for any reason). So far I understand it is fairly easy and might prevent any instance to force/capture users. Until custom features are introduced, this should be ok.

@randomwalker And of course if another Elon manages to buy the biggest few instances, migration will be a lot easier!