Mark Zuckerberg made his first public appearance since Facebook’s IPO in May and he said that mobile was fundamental to Facebook’s future and that it would make more there than it would on the desktop.

Facebook had come in for criticism in recent months for not explaining fully how it planned to monetise mobile, which is seen as crucial for its long term future.

Speaking at TechCrunch Disrupt, where he spoke with founder turned venture capitalist Michael Arrington, Zuckerberg admitted there had been mistakes: “There is no doubt we had a bunch of missteps on this. But we’ve transitioned now and we are a mobile company.” 

He said moble was fundamental to Facebook’s future and outlined some of the reasons why. Chief among those was that levels of engagement on mobile are far higher when compared to the desktop.

“It’s easy to underestimate how fundamentally good mobile is for us. First, there are more users. Second is, per person who’s using Facebook on mobile, there’s more engagement and they’re spending more time. Third, per person on mobile, we think we’re going to make more money on them than on desktop.”

Since Facebook launched the latest version of its app for Apple’s mobile operating system, iOS, Zuckerberg told the audience that users were reading double the amount of posts and other content.

HTML5 missteps

One of the missteps that Zuckerberg was talking about was betting on HTML5 to build mobile versions of Facebook instead of opting for native apps. That was a mistake, Zuckerberg said. It was a costly one that sucked up two years of development time.

“We went for this approach. It’s really painful. It’s one of the biggest mistake if not the biggest strategic mistake we made. We’re coming out of that.”

The Facebook phone?

There have been many reports over the last year saying that Facebook was working on its own phone, codenamed Project Buffy, and yesterday Zuckerberg took time to quash any talk that this was ever going to happen.

“Do you believe me yet? It’s always been such a juicy story, but it’s so clearly the wrong strategy for us. Theoretically. We’re not. We could get 10 million, 20 million people to use it. That doesn’t move the needle for us!”

Zuckerberg’s life on mobile

To give the audience an idea of what he personally does on his mobile, and how essential it is to his life, Zuckerberg said that he wrote Facebook’s pre-IPO S1 registration statement on his phone.

“I basically live on my mobile device. You know the founder’s letter in the S-1? I wrote that on my phone.”

Zuckerberg’s S1 statement was the one that said “we don’t build services to make money; we make money to build better services”.