NEW YORK (CNNMoney) -- Twitter's chief revenue officer won't reveal specific numbers around the company's financials, but he says the company's ad-fueled business model is succeeding.
Twitter now has 2,400 advertisers, up from 1,600 in the spring, CRO Adam Bain said Wednesday during a conference in New York City, hosted by Business Insider.
"The big question we thought we were going to face with advertisers was, 'Why Twitter?'" Bain said. "But they already knew why Twitter. The question was more, how?"
Twitter offers three types of ads: promoted accounts, promoted trends and promoted tweets, which appear in users' content streams. These types of ads draw "massive engagement," Bain said, with a conversion rate of about 3% to 5%. The rate for traditional display ads is around 0.5%.
"The [return on investment] for marketers is insane," Bain said, citing a handful of successful campaigns. Audi plugged a hashtag at the end of its Super Bowl ad on TV, and three months later, the tag was still popping up on Twitter.
Bain also talked at length about a deal with Paramount earlier this year, in which Twitter promoted the movie "Super 8." More than 1.5 million tickets were sold that way, Bain said.
"So what did Twitter get for that? Six figures?" asked Henry Blodget, the editor-in-chief of Business Insider.
Bain wouldn't say. He instead focused on how Twitter offers more user engagement than traditional display ads.
Blodget used that as a segue into a question about one of the tech world's famously troubled giants -- one that relies heavily on display advertising sales.
"So, Yahoo (YHOO, Fortune 500): screwed?" Blodget asked.
"Uh, well, I think the portals are in a difficult place for proving their value to marketers," Bain replied.
"Very diplomatic," Blodget said with a laugh.
Twitter's focus for this year and next year is to continue scaling the business, Bain said.
"There are 7 billion people in the world. Maybe 6 billion with a phone connection. We're not going to stop until we touch every single one of them," Bain said. "This is going to be a massive business. It already is."
Bain ducked a question about some of the business's pain points. Blodget asked about the exodus of some top Twitter talent this year, and whether there's "a turnover problem at Twitter."
"You know, it's very easy to focus on the small things," Bain said. "But what gets ignored is that we've hired tons of people in the past year."
Bain also skirted a pointed query about Twitter's management and the dynamic between CEO Dick Costolo and co-founder Jack Dorsey, who was once exiled from the company but returned earlier this year to run product development.
"Who actually is the boss at Twitter?" Blodget asked.
"It's easy fall into the trap that one is a product guy and another is an operations guy. But they flex both muscles," Bain replied.
Blodget expressed skepticism about how well Dorsey can balance his Twitter duties with running his own venture, Square, a mobile payments platform. But Bain was quick to defend him.
"Even when Jack wasn't at Twitter anymore, he never stopped thinking about the product," Bain said. "He has a crystal clear vision for the product. And that's what you need." 
