Users pay £6 a week for full access to The Times and Sunday Times content, including tablet and smartphone apps. Speaking at Rethink Media, Alan Hunter said that subscription levels were "very good," adding that they were "steadily going up".
"In 2009, Times Newspapers lost £72 million in a single year," he said. "Now we're down to £6 million [for trading year ending June 2013] and we're actually moving towards profit."
"The situation actually is much more rosy than I think any of us would have thought five years ago."
Charging for content, said Hunter, enabled The Times and Sunday Times to improve its digital offering, as well as pursue stories which could be expensive to produce.
As an example, he cited the Sunday Times' long-running legal battle with David Hunt – who made a claim for libel but lost – which Hunter said had cost "an awful lot of money".
He argued that readers were willing to pay for content which was covered in the public interest.
"We think we were doing a public good [with the Hunt story], and our readers certainly seemed to back that and want to pay for that," he said.
User engagement was an important measure of success for the sites, he added, and was a more important measure to the outlet than traffic levels.
"We're not in the click game, we are basically after people's attention," he said.
Key to the Times and the Sunday Times strategy, he added, was to produce content aimed at encouraging high levels of engagement through stories, videos and various interactives.
"Our [traffic] numbers look like rounding errors compared with BuzzFeed's numbers, but what we rely on is the fact that the people who come to us are engaged," he said.
To emphasise this point, he noted that people were using The Times iPad app for on average 40 minutes a day, which, he added, "is an amazing amount of time given the amount of drive-by hits that many sites get".
Another key principle behind what The Times is now calling its "membership" (rather than subscription) model, is the idea that people want to feel part of a "news-based community".
Hunter said this model had encouraged a "higher standard" of on-site discussion due to the fact that all comments are attributed to a named subscriber.
"The volume [of comments] is much lower than on other sites, but the standard is better and a lot of the writers also get involved," he said.
He added that feedback from readers suggested the main reason they subscribed to the sites was to "be part of a news community".
But despite the decision to move content behind a paywall, Hunter said that the core principle of The Times and the Sunday Times remained the same.
"We have to keep doing what we've always done," he said, "which is to tell great stories and tweak the nose of authority and do what great journalism has always been about."