Twitter continues rapid growth as advertiser numbers soar.

Twitter is seeing explosive growth as advertisers continue to flock to the website, according to its chief executive.

The social networking website is now growing faster than it has ever done before, Dick Costolo said at the Fortune Brainstorm Tech conference in Colorado, US.

More than 200 million people have signed up to use Twitter and its users send more than one billion tweets every five days, AFP reported.

Mr Costolo said the number of advertisers on the website was up by 600% compared to last year's figures. The advertising system is organic to Twitter because promotions just appear as tweets, he said.

Twitter allows advertisers to tailor a campaign in real time and get it to a global market. Mr Costolo said film studios had increasingly used the system to promote trailers the week before a movie arrives in cinemas.

Four out of five advertisers have been renewing their campaigns because of the response they receive. Mr Costolo said: "Our engagement rates are through the roof, ads with clickthrough rates of 30, 40, 50 percent."

Advertising will play a key role in Twitter's future as a business and the social networking website is also looking to commerce to increase revenue, he said.

Although Mr Costolo did not say whether Twitter is profitable at the moment, retaining current advertisers and attracting new companies can only be good for the firm's balance sheet and future growth.