Twitter is putting to rest any doubts it is taking a shot at being one of the Web’s next big platforms with a $200 million funding round that values the company at a staggering $3.7 billion.

AllThingsD.com reported details of the round, which will also bring former DoubleClick CEO David Rosenblatt and Flipboard CEO Mike McCue to its board of directors. (Twitter has confirmed the funding round and new board members.)


The funding round comes after Twitter reportedly spurned acquisition feelers from Google. It is a huge bet for investors, led by Kleiner Perkins, that Twitter can grow to become a tech platform alongside Google, Facebook, Apple and others. With its 175 million registered users posting short updates, Twitter could theoretically build “ the communications graph” to operate alongside Facebook’s social-connectivity graph.


Rosenblatt, who served as president of Google’s display ad business, will bring to Twitter his deep knowledge of the online ad business. He’s been a director at other companies, including GSI Commerce, where he joined the board last month.


The question is whether Twitter can build a big enough ad business to justify its high-flying valuation. To date, it’s run very few ads, choosing instead to create ad products in-line with how its service is used. Rather than display ads, Twitter is offering promoted tweets, trends and accounts.


Dick Costolo became CEO of the company in October with an eye to turning it into a formidable ad business. Its sales force, under Adam Bain, remains tiny; and Twitter does not yet have an office in New York. - Ad Week