Similarweb: US DAUs of Bluesky's mobile app grew 12% MoM in December vs. 284% MoM in November; Bluesky now has 26.44M+ total users after passing 20M in November
X has ~18m daily USA users. @bsky.app, ~1.5m. — Is it worth 20 MINS a day to proactively recruit and bring your friends, neighbors,relatives, businesses, anyone who is or could be a user, to @bsky.app? — If Bluesky ends up with more users than the others, you destabilize musk, zuck, trump. Mark Cuban / @mcuban : IF YOU BELIEVE THE MANY SHOULD HAVE CONTROL OVER THE FEW, this is your time. — As a decentralized platform, @bsky.app is probably the last, best chance for this to happen — This has nothing to do with me. I'm just stating the obvious. — It has everything to do with what the 1.2m @bsky.app users do. Threads: Sarah Perez / @sarahprz : After X exodus, Bluesky growth slows in December: https://techcrunch.com/... See also Mediagazer
Context & Ripple Effects
Bluesky’s December activity growth followed a November acquisition burst in which it crossed 20 million users, making the lower month-over-month rate a shift from breakout adoption to retention and repeat use.
The platform’s rise has also coincided with declining US daily activity at X, though Bluesky’s reported US mobile audience remains much smaller. The comparison makes the quality of Bluesky’s post-surge engagement more consequential than its cumulative sign-up count alone.
First-order effects
- Bluesky adds more than 6 million total users beyond its November 20 million milestone, while US mobile daily activity continues to rise in December.
- The deceleration from 284% to 12% month over month means Bluesky’s immediate challenge shifts from absorbing a rapid influx to keeping newer users active.
Second-order effects
- X and other social platforms face a more durable competitive signal if Bluesky can convert its November cohort into regular users, rather than merely attracting downloads during a migration spike.
- For Bluesky, product, moderation, and community decisions become more important to growth: slowing percentage gains make retention and user-to-user recruitment a larger share of incremental activity.
Third-order effects
- The episode fits a broader contest for social-network route share: user dissatisfaction can trigger rapid migration, but long-term market reallocation depends on whether alternative networks sustain daily habits.
- If repeated migration waves continue to favor decentralized alternatives, social competition may be shaped less by one-time sign-up surges and more by portability, community resilience, and switching friction.
The trend: Bluesky’s December figures are an early test of whether a protest-driven social migration can mature into durable daily usage on a decentralized network.