The news: Bluesky’s upward trajectory is accelerating as the social network startup saw one of its biggest growth spurts last week. The platform gained 1 million users in a single day, pushing its user base to more than 16 million.

Competition in the microblogging space outside of X (formerly Twitter) is heating up—Threads said it plans to launch customized feed options, a key feature of Bluesky’s offerings, and will start testing ads in January.

Expanding field: Although Threads’ user count is more than 10 times larger than Bluesky’s, it’s also garnering more complaints. And its addition of ads could both attract marketers and alienate users.