Crosslink Capital and previous investors Adams Street Partners and Trinity Ventures also participated in the financing for the San Francisco-headquartered business, which opened an office in London in January this year. Fundraising for RadiumOne now totals $33.5 million.

According to a RadiumOne statement, the equity investment will be used for international expansion and acquisitions. The business plans to open further offices in continental Europe and Asia-Pacific.

RadiumOne founder and chief executive Gurbaksh Chahal says the company, which reached profitability at the end of last year, will use its existing and new capital for potential acquisitions that will give the company ‘additional resources and tools to effectively scale’.

He comments, ‘The social evolution of the internet has given us an opportunity to do this, and we feel we’re filling the void of socially-targeted advertising outside of Facebook. This latest round of funding will accelerate our growth.’

Since launching 18 months ago, the company has signed up more than 500 companies to its technology that analyses how computer users communicate with their closest connections.

Krishna Visvanathan, partner at DFJ Esprit, adds, ‘Leveraging social data to improve online advertising is a truly exciting arena and we are pleased to be backing a company making a real impact in this space.’