Twitter Chief Financial Officer Anthony Noto confirmed Wednesday that he is running the company's marketing department -- a move that has mystified people in the media and marketing world since it was first reported weeks ago.

Mr. Noto told investors at the JP Morgan Global Technology, Media, and Telecom conference in New York why he's taken on this additional role. Twitter's board wants to elevate the "importance of marketing as a key component of everything we do … but marketing really needs to permeate product, it needs to permeate content and it needs to permeate media and it's a really huge opportunity in front of us."

The decision to put Mr. Noto in charge of marketing raised questions because finance guys aren't typically associated with marketing savvy. "Marketing is just not something a CFO is trained in," Kevin Keller, a marketing professor at Dartmouth's Tuck School of Business, told Ad Age recently. "They don't have the instincts or experiences."

It was also puzzling because investors are nervous about Twitter's user growth. The company's stock plunged roughly 20% on April 28 after reporting its weakest quarterly revenue increase since going public.

Mr. Noto on Wednesday articulated the challenge Twitter faces: The company has very high brand awareness, but that hasn't translated to new users.

"The opportunity is to establish a very clear brand value proposition, to have that permeate our content, have it permeate our product development and then to communicate it through integrating marketing programs," he said.

Later, Mr. Noto added, "I think we've a significant opportunity to educate the 75% of people that don't use Twitter that should use Twitter on the value proposition it provides, and consumption-first experience is the way to do that, marketing is the way to do that."

But don't necessarily expect an expensive TV marketing campaign, according to Mr. Noto. "We're very early days in our thinking," he said. "We're doing significant amount of market research, consumer segmentation research by geographies that are important. We're going to establish what the opportunity is and we will invest appropriately based on the returns and the value we think it can drive over time and we'll do it in a prudent way like we've done everything else."

What he didn't address, however, is why Twitter hasn't tapped someone with a marketing background to run this department. The company has spent the last several months looking for a chief marketing officer and some have suggested that Mr. Noto is simply a high-ranking placeholder until that person is hired.

Twitter didn't immediately respond to an Ad Age email posing that question.