Major social networks by year: four shifts in who sees what

The interesting thing about social networks over time is not which ones existed. Major social networks by year settle into four shapes, and each shape rewrote the answer to one question: who sees what you publish?

Topic-first is the oldest shape. CBBS, switched on in Chicago in February 1978 by Ward Christensen and Randy Suess, filed messages under subject boards. Usenet followed in 1979, built at Duke and UNC by Tom Truscott and Jim Ellis, with posts sorted into hierarchies such as comp, sci and rec.

A platform's category (forum, feed, recommendation engine), tells you more about how it will behave than its name does, which is why the side-by-side method starts from structure rather than from features.

What to take away

Four shapes, in order: Usenet, Six Degrees, the News Feed, TikTok

Topic first, 1978 to the mid 1990s. You went to a place about a thing: a Usenet group, a CompuServe forum, a local bulletin board, a WELL conference. CompuServe opened its consumer service in 1979. The WELL started in 1985 in Sausalito, California, run by Stewart Brand and Larry Brilliant.

Conversation accumulated under headings, stayed there, and remained readable for years. Who saw what you wrote was decided by the subject you filed it under and by whoever came looking for that subject afterwards. Your identity mattered only as reputation within the room.

AOL, launched in 1985, ran the same shape with keyword rooms, and its Instant Messenger arrived in 1997.

Person first, 1997 to about 2005. Six Degrees opened in 1997 with profiles and friend lists, and closed in 2001. Friendster followed in 2002, MySpace in 2003, LinkedIn in May 2003, and Facebook in February 2004.

A profile became the unit, and the connections between profiles became the structure, which is the point at which a social graph became a thing a company owned. Who saw your post was decided by an explicit list of people who had agreed to be connected to you.

Membership was mutual, so the graph stayed roughly the size of a real social circle, and content was addressed to people who knew you. News Corp bought MySpace for $580 million in July 2005, and Microsoft bought LinkedIn for $26.2 billion in June 2016.

Orkut, Google's person-first network from 2004, held Brazil and India for years and closed in September 2014. Friendster shut its social network in 2011 after a turn toward gaming.

The feed, 2006 to about 2015. Facebook's News Feed arrived in September 2006 and assembled a single column from everyone you followed. Twitter launched publicly in July 2006 with one-directional following, so audiences could grow past the size of a social circle and strangers could follow without asking.

Two things changed at once. Following became one-directional. Ordering became a design decision, initially just reverse chronology. That is still a decision with consequences: it rewards posting when your audience is awake and it buries anything published into a quiet hour.

Instagram launched in October 2010, built by Kevin Systrom and Mike Krieger, and Facebook bought it for $1 billion in a deal announced in April 2012. Tumblr, started in 2007, sold to Yahoo for $1.1 billion in 2013.

Ranking, then recommendation, 2011 to now. Facebook began ranking the News Feed with EdgeRank around 2010, reordering the things you subscribed to and keeping your choices as the input. Twitter added an algorithmic timeline in February 2016, after testing "While you were away" in 2015. Instagram switched to a ranked feed in June 2016.

Recommendation drops the requirement that you subscribed at all: the system selects from everything on the service, and your follow list becomes one signal among many. TikTok's For You page, built on ByteDance's Douyin from September 2016, works that way. YouTube ranked by watch time from 2012.

At that point the network stops being a network in any meaningful sense. It is a distribution system with a social layer attached. Meta's Threads took 100 million signups in its first five days in July 2023, and Facebook retuned its ranker in 2018 to favor "meaningful interactions."

What each shift did to who sees what

Read down the "who decides" column and the whole arc is visible in one line: distribution power moved from the subject, to the reader, to the clock, to the ranker.

The consequences that persist

The subscriber guarantee dissolved. Under the first three shapes, an audience that asked for your work received it. A Twitter follow or a Facebook friend request worked that way. Ranking weakened the deal and recommendation ended it. Follower counts now describe eligibility rather than delivery, and the gap varies by platform.

Reach became rented. Once a system decides distribution, the relationship between a creator and an audience runs through a third party that can adjust it. Facebook, Instagram, X and TikTok have all changed how much reach a post gets without warning. Hold a contact route the platform cannot alter, such as an email list.

Durability collapsed and then partly returned. Topic-first spaces produced archives that answered the same question for everyone who arrived later, because search engine indexing could reach them and a stranger could land in a five-year-old thread. Feeds produced streams where a post's useful life is measured in hours.

Recommendation is a strange hybrid: it can pull something old back into circulation, but unpredictably and not because anyone searched for it. Usenet's archive survived on Google Groups until February 2024, when Google dropped support for it. Durability now tracks the ranking system's appetite, not the format.

Discovery moved from pull to push. Finding things by looking for them was replaced by being shown things. YouTube's home feed and TikTok's For You page decide what you see before you type. That favors whatever the ranker can evaluate quickly, which is not the same as whatever is best.

Topic organization came back informally. Interest-based grouping is useful, so it returned in weaker forms: Reddit's subreddits after 2005, Facebook Groups in 2010, Discord servers in 2015, hashtags on Twitter from 2007. Structure that gets removed by design tends to reassemble somewhere.

The moderation load grew with the audience. Under person-first structures, most content reached people who knew the author, and social pressure did a lot of quiet work. When distribution routinely reaches strangers, that mechanism stops working, and moderation has to be done deliberately, at scale, by someone.

How to use the arc when comparing platforms

You do not need the history to place a platform. You need the categories.

Every fix moved distribution power one step further from the reader and the author. The federated and protocol-based designs are best understood as an attempt to move it back, at a price. Mastodon has run since 2016 as a nonprofit project in Germany, and Bluesky opened to the public in February 2024 on the AT Protocol.

Figures attached to any of this (how large a shift was, how many people it affected), should be checked against a primary source before use, for the reasons set out in the notes on how platform facts are counted.

Common questions

Is chronological ordering better?

It is more predictable, which is a virtue, and it is not neutral. Twitter ran on reverse chronology from 2006 to 2016. That rule favors whoever posts most and posts at the right hour. Every ordering rule is a policy about who gets seen; the honest question is which policy, not whether one exists.

Why do old shapes keep coming back?

Because they solved problems the new shapes reintroduced. Durable topic archives, small mutual groups, and direct subscriptions keep reappearing as a reaction to the costs of ranked distribution. Reddit's subreddits, Facebook Groups, Discord servers and email newsletters are the current versions. Expect them reinvented under new names rather than gone.

Does this mean building an audience is pointless?

No: it means being precise about what you are building. An audience on TikTok or Instagram is a stream of attention you are currently being granted. An audience you can contact directly, by email or RSS, is an asset. Do the first for reach and convert as much as you can into the second.

How do I tell which shape a new service is?

Sign up, follow nothing, and look at what you are shown. A blank screen means subscription-led, the way Twitter looked in 2006. A full one means recommendation-led, the way TikTok's For You page looks. That test takes a minute and tells you more than the marketing.