Oath, the new digital advertising and media company that combines AOL and Yahoo, has a monstrous challenge ahead.

Google and Facebook control almost two-thirds of the online ad market, according to eMarketer. Verizon — the parent of Oath — is stuck below 5 percent and in a tie for third with Microsoft.

Beyond trying to track down two of the world’s most valuable companies, Oath has to overcome Yahoo’s recent data breaches, which further damaged an already troubled reputation. Yahoo‘s platform has also been accused of high levels of ad fraud by its customers, with sources previously telling CNBC that ads didn’t run in the right place and many of the viewers were actually bots.

But Oath is talking a big game.

By merging its disparate ad platforms and expanding its media properties in Latin America, Asia and Europe, the company plans to double its reach to 2 billion people in the next three to five years. It’s also working with third parties to provide more transparency in telling marketers where their ads are running.

John DeVine, Oath’s chief revenue officer, expects those efforts to result in major market share gains.

“We want to move the ball forward around the theme of trust, and we don’t want to stop at number three,” DeVine told CNBC.

Oath recently launched its first global advertising campaign called #BuildYourBrand to reintroduce AOL and Yahoo as one company to advertisers and the public. The companies were acquired by Verizon in 2015 and 2017, respectively.

In aiming to reach more of the projected 5 billion internet users worldwide by 2020, Oath is emphasizing mobile experiences, DeVine said. It’s focusing on sports, news and finance coverage and going heavy on original video, especially sports and live events. Yahoo had the exclusive rights to the first London NFL game this September. The company plans to acquire more concerts and international sports and is evaluating the rights to cricket matches.

Tim Mahlman, Oath’s president and head of programmatic ad tech platforms, said there’s also an opportunity to provide production facilities and license syndicated video to Oath’s media partners.

“We have the tools between our two companies that allow us to take video content and expand it out to where it isn’t today,” Mahlman said.

As for the data breaches, DeVine called it an “industry problem” and pointed to the latest hack involving Equifax. He said that following Yahoo’s two major hacks last year, the company was able to rebuild its relationships with users rather quickly.

“We’re all going to continue to fight this together,” DeVine said. “We feel like were on a very good trust footing with our consumers, and we’re going to continue to earn that every day.”