Twitter says 80% of UK users access the site via mobile devices.
The microblogging service boasts over 500 million registered and 140 million active users worldwide. Twitter identifies an active user as someone that uses the site every 30 days.
Twitter announced the 10 million milestone on its site, pointing out it’s increasing presence on mobile.
The company opened its London office 12 months ago which currently has a staff of 30 people.
Twitter’s announcement comes after the site confirmed its plan to launch an email digest service for its users.
The new service will send users the most relevant tweets and stories from people they are connected to on Twitter.
"Stories feature a design similar to the recently updated Discover tab, emphasizing who shared each story beneath summaries to help you decide which ones matter most to you," says Othman Laraki, Director of Growth and International at Twitter. "Click any headline to finish reading the story, add your take by tweeting directly from the email, and see related Tweets from the people you follow."
Twitter will be rolling out the new email over the next few weeks.
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