STORY: As billionaire Elon Musk approaches a Friday deadline to close his $44 billion deal to buy Twitter, Reuters has exclusively learned that the social media company is losing its most active and important users.

That's according to an internal Twitter document seen by Reuters, titled “Where did the Tweeters Go?” in which a Twitter researcher wrote that so-called "heavy tweeters" have been in "absolute decline."

The internal document said a "heavy tweeter" is defined as someone who logs in to Twitter six or seven days a week and tweets about three to four times a week.

These "heavy tweeters" account for less than 10% of monthly overall users but generate 90% of all tweets and half of global revenue.

The research also found that cryptocurrency and "not safe for work" content, which includes nudity and pornography, are now the highest-growing topics of interest among Twitter's most active English-speaking users - a shift over the past two years that could make the platform less attractive to advertisers.

At the same time, interest in news, sports and entertainment is waning among those users - topics that are most desirable for advertisers.

The study said Twitter was motivated to investigate “disturbing” trends among users and better understand the decline in the company’s most active users.

Asked to comment on the internal documents' findings, a Twitter spokesperson said: "We regularly conduct research on a wide variety of trends, which evolve based on what’s happening in the world. Our overall audience has continued to grow, reaching 238 million mDAU in Q2 2022."

The study made no specific conclusions about why heavy users are declining but a Twitter researcher wrote that these users are likely decamping to rival platforms like Instagram and TikTok.