Pinterest Inc., the Internet scrapbooking startup that was most recently valued at $3.8 billion, is finally turning on the money spigot.

Advertisers can now pay to more prominently display their pins, which are the pictures of products that get shared through the site, the San Francisco-based company said in a blog post today. Pinterest has been experimenting with the ads, called promoted pins, since October when it raised $225 million.

The rollout of the ads has been a long time coming. Pinterest, which was started in 2010, has been under scrutiny because while it has gained users and attracted funding, it has brought in little revenue to justify its high valuation. Chief Executive Officer Ben Silbermann has said he wanted to move slowly on a business model to avoid alienating users.

“Brands help people find inspiration and discover things they care about, whether it’s ideas for dinner, places to go or gifts to buy,” Joanne Bradford, head of partnerships at Pinterest, said in the blog post. “We hope promoted pins give businesses of all sizes a chance to connect with more pinners.”

Among the advertisers that are trying promoted pins are retailers such as Target Corp. and Gap Inc. and some of its brands, according to the post. Kraft Foods Group Inc. and General Mills Inc. are also paying for the ads.

Natural Pins

Bradford said in an interview that she has been aggressively hiring people to work with brands. She said her team has tripled in size since she joined in December, and she still has 20 open positions. The company has held workshops for advertisers on what works best on the site, she said.

“There are no banners stuffed in, there is no crazy experience — pins are part of the brand,” Bradford said.

Pinterest now hosts 750 million pinboards and 30 billion pins, Silbermann said in April. His team has been updating the product to make it easier for users to find what they’re looking for, unveiling a new guided search function for images last month.

Pinterest has raised at least $565 million from investors including Fidelity Investments, Rakuten Inc., Bessemer Venture Partners and FirstMark Capital.

To contact the reporter on this story: Sarah Frier in San Francisco at To contact the editors responsible for this story: Pui-Wing Tam at Jillian Ward

Photo Credit: Promoted fashion pins by Gap, now live on Pinterest.