Bluesky's growth trajectory — with a user base that has more than doubled since October — could make it a serious competitor to other social platforms. But with growth comes growing pains.
It's not just human users who've been flocking to Bluesky but also bots, including those designed to create partisan division or direct users to junk websites.
The skyrocketing user base — now surpassing 25 million — is the biggest test yet for a relatively young platform that has branded itself as a social media alternative free of the problems plaguing its competitors.
According to research firm Similarweb, Bluesky added 7.6 million monthly active app users on iOS and Android in November, an increase of 295.4 per cent since October.
It also saw 56.2 million desktop and mobile web visits, in the same period, up 189 per cent from October.
Besides the US elections, Bluesky also got a boost when X was briefly banned in Brazil.
"They got this spike in attention, they've crossed the threshold where it is now worth it for people to flood the platform with spam," said Laura Edelson, an assistant professor of computer science at Northeastern University.
"But they don't have the cash flow, they don't have the established team that a larger platform would, so they have to do it all very, very quickly."
To manage growth for its tiny staff, Bluesky started as an invitation-only space until it opened to the public in February.
That period gave the site time to build out moderation tools and other distinctive features to attract new users, such as "starter packs" that provide lists of topically curated feeds.
Compared to the bigger players like Meta's platforms or X, Bluesky has a "quite different" value system, said Claire Wardle, a professor at Cornell University. This includes giving users more control over their experience.
"The first generation of social media platforms connected the world, but ended up consolidating power in the hands of a few corporations and their leaders," Bluesky said on its blog in March.
"Our online experience doesn't have to depend on billionaires unilaterally making decisions over what we see. On an open social network like Bluesky, you can shape your experience for yourself."
Because of this mindset, Bluesky has achieved a scrappy underdog status that has attracted users who've grown tired of the big players.
"People had this idea that it was going to be a different type of social network," Wardle said.
"But the truth is, when you get lots of people in a place and there are eyeballs, it means that it's in other people's interests to use bots to create, you know, information that aligns with their perspective."
Little data has emerged to help quantify the rise in impersonator accounts, artificial intelligence-fuelled networks and other potentially harmful content on Bluesky.
But in recent weeks, users have begun reporting large numbers of apparent AI bots following them, posting plagiarised articles or making seemingly automated divisive comments in replies.
Lion Cassens, a Bluesky user and doctoral candidate in the Netherlands, found one such network by accident — a group of German-language accounts with similar bios and AI-generated profile pictures posting in replies to three German newspapers.
"I noticed some weird replies under a news post by the German newspaper 'Die Ziet,'" he said in an email to The Associated Press.
"I have a lot of trust in the moderation mechanism on Bluesky, especially compared to Twitter since the layoffs and due to Musk's more radical stance on freedom of speech. But AI bots are a big challenge, as they will only improve. I hope social media can keep up with that."
Cassens said the bots' messages have been relatively innocuous so far, but he was concerned about how they could be repurposed in the future to mislead.
The company didn't respond to multiple requests for comment for this story.
