SAN FRANCISCO -- Pinterest has secured a $225-million round of funding that values the company at $3.8 billion.

With the funding led by Fidelity Investments, Pinterest becomes one of the most valuable privately held consumer Internet companies even before it proves it can cash in on its popularity.

Last month, the San Francisco company announced it planned to test a new advertising product called “promoted pins.”

  • Also

“We hope to be a service that everyone uses to inspire their future, whether that's dinner tomorrow night, a vacation next summer, or a dream house someday. This new investment enables us to pursue that goal even more aggressively,” Chief Executive Officer Ben Silbermann said in an emailed statement.

As Twitter prepares for its hotly anticipated initial public stock offering next month, Pinterest has emerged as the next big thing among privately held companies.

Still, Pinterest has a lot to prove. According to a recent survey from Reuters and Ipsos, 26% of 807 people polled said they had signed up for Pinterest but no longer used the service. Nine percent of people who signed up said they had shut down their accounts.

Pinterest said it would use the capital to expand internationally. The service recently launched in Britain, France and Italy and Pinterest is looking to add 10 more countries before the end of the year.

Mobile will also get a chunk of the cash. Mobile has grown 50% to account for more than three-quarters of all activity on Pinterest, the company said.

It will also roll out its “promoted pins” advertising program worldwide, the company said. It began testing the ads earlier this month.

In addition, Pinterest will put money into making its service faster and more reliable and into buying up companies to bring on more engineers and technology.

Previous venture capital investors, including Bessemer Venture Partners, Firstmark Capital, Valiant Capital Management and Andreessen Horowitz, also participated in the latest round.

Just last May, Pinterest had a valuation of $1.5 billion.

The funding was first reported by technology blog AllThingsD.

ALSO:

Pinterest in talks to raise funds at up to $2.5-billion valuation

Pinterest makes first move to make money with 'promoted pins'

Pinterest pins hopes on broader appeal on holiday marketing push