Flock has taken $15 million Series D in a round led by Fidelity Ventures that included previous investors Bessemer Venture Partners, Catamount Ventures and Shasta Ventures.
Flock is a social web browser built on the code for Firefox. Flock defines itself through integrating various social networking sites and services from within the browser, including MySpace, Facebook, YouTube, Twitter and others.
Flock’s user base has grown 250% since January this year, with revenue rising by more than 400% over the same time period. Flock was named the winner of the Webby Award in the Social Networking category, beating both Facebook and Bebo.
Flock said that the new funds would be used to provide growth capital to expand Flock’s business, including research and development, marketing and expansion into new global markets.