(Reuters) - Meta Platforms' newest social media offering Threads has over 175 million monthly active users, CEO Mark Zuckerberg revealed on Wednesday, ahead of its first anniversary.

A challenger to X, formerly known as Twitter, Threads hit app stores on July 5 last year, timed to win users from the de facto micro-blogging site during its chaotic takeover by billionaire Elon Musk.

It garnered 100 million users in less than a week, partly because of an easy way for users of the popular platform Instagram to set up their Threads profiles, but some early users subsequently dropped off. 

"What a year," said Zuckerberg in a Threads post. In April, he had put the Threads MAU figure at more than 150 million.

The monthly average user count gives only a limited picture of the popularity of Threads, which has not revealed key metrics such as the daily active user count and average time spent per user.

Although Threads grew the number of users through international expansion and new features, the platform has struggled to drive engagement, according to market intelligence firm Sensor Tower.

Last month, users registered an average of three sessions and seven minutes a day on the Threads app, down about 79% and 65%, respectively, from July last year, as per Sensor Tower data.

Threads does not have advertising and, as such, makes little to no money for Meta. The platform recently came on the Fediverse, a group of social media sites that support the ActivityPub protocol and whose users can interact across those platforms.

"A year after launch, we know what Threads isn't, but we don't know what it is," said eMarketer analyst Jasmine Enberg, adding that a lack of direction and original content could plague its growth.

"Meta must be wondering whether it makes sense to keep Threads as a standalone app or to direct that engagement back to Instagram. The good news is that advertiser interest in the platform is high," she said.