The micro-blogging site Twitter has said active users have passed the 100 million mark, but it has no plans to become a public company.
The company’s chief executive told a news conference it was preparing to increase its business range by broadening the areas of its service where adverts appear.
But Dick Costolo also said he wanted the business to remain independent.
He said active users, who log on at least once a month, rose 82% this year.
Half of these 100 million log on at least once a day.
Twitter raised $400m (£250m) in venture capital funding this summer.
Mr Costolo said: “We want to be able to remain independent, grow the business the way we want to, and not be beholden to public markets until we feel like we want to be.”
The company began showing adverts in limited areas of its service in 2010.
But it is concerned that commercialisation sometimes alienates users of social media.
More advertsMr Costolo said the results had exceeded Twitter’s expectations: “We now feel that based on the engagement rates we’re seeing… that we’re ready to expand this further.”
Twitter plans to allow adverts on its service known as promoted tweets.
Previously, promoted tweets, such as a message promoting a coffee chain, would only appear if the user already followed that particular company.
Mr Costolo said the business could work relying solely on advertising income: “It’s our firm belief that our advertising platform is the only revenue component that we need to have in the market in order to be a huge independent business.”
Twitter allows people to send 140-character messages, or Tweets, to anyone who signs up to receive them.
It has 200 million registered users, while Facebook has 750 million.