Social media site boosted by DST Global's $400m, as value doubles since December and daily traffic triples in a year

Twitter, the microblogging site that allows users tweet messages of 140 characters or less able, is now worth $ 8 billion (? 4.9 billion). The company 's new price tag comes after a 400 million dollar investment in the loss-making venture of serial DST Global Social Media Investors. Twitter is now nominally worth about the same as rating agency Moody 's, which had sales of $ 1.2 billion in the first six months of 2011 and is almost as valuable as Marks & Spencer.

The huge rating reflects the high expectations of the company. Confirmation of investment, Twitter also announced that its users can now send 200 tweets per day, up from 65 last year.

"A year ago there were approximately 150,000 registered Twitter apps. Well, there is more than a million to join the Twitter. And our team has grown from 250 people more than 600 in the last 12 months," said the company In a blog post.

"We have the ability to Twitter 's reach with a significant round of financing by venture capital firms led DST Global to expand, with the participation of several of our existing investors," said Twitter. "We will use these resources to the offensive innovation, hire great people and invest more in international expansion."

The new funds are part of $ 800m Twitter wants to raise as his shop keeper for a possible IPO. DST Global, the investment fund run by Yuri Milner Russian billionaire, also owns shares in Facebook, online gaming company Zynga and reduced company Groupon, all plans have to go public.

Twitter is believed to be using half the money to buy back shares from employees and backers. The rest of the money will be used to help the San Francisco-based company develop its service as it competes for advertising dollars with larger rivals such as Facebook. Twitter may bring in $150m in advertising this year, according to research firm eMarketer, three times what it made last year. The analyst estimates that Facebook brought in ad revenue of $1.86bn last year.

Twitter \ s top social media company's rating has risen along with his colleagues as investors hunt for the world ". At $ 8 billion Twitter 's assessment is more than double the assessment he received last December, as the Silicon Valley investor Kleiner Perkins Caufield & Byers made $ 200 million investment in the company. The new money brings Twitter 's investment of just over $ 1.16 billion over four years.

The company also needs money to build their international business. Twitter has London as the first major office outside the U.S. specifically appointed and that a British head, Tony Wang, a resident and employee communications in the UK.

Twitter 's new rating comes as shares in the social media companies now consider the public frenzied buying. Shares in LinkedIn, the business-based social media company, jumped more than 80% in its first trading day. You must be doubled to more than $ 45 opening price and the trading company is valued at $ 9.5 billion.

But not all of the new generation of social media companies have fared so well. Pandora, an online music company, priced its shares at $ 16 per piece, and saw a big bounce on the first day, but now trade at about $ 13

Renren, often called China's Facebook, soared 28.6% on its first day of trading in May, closing at $18 a share, well above its $14 opening price and raising $740m. The shares have subsequently slumped to about $10 as investors worry about lack of profits and the Chinese market.