Jeff Bezos made his fortune founding Amazon, and spent $250 million of that fortune buying The Washington Post in 2013.

After nearly four years running the Post, which Bezos says turned a profit in 2016 and is expected to do the same this year, Bezos has some valuable lessons to pass along to the rest of the news industry, which is struggling to compete for ad dollars against online juggernauts Google and Facebook.

Bezos delivered some of this advice at the Future of Newspapers conference in Turin, Italy, on Wednesday. Here are the highlights:

Focus on readers first, not advertisers. In response to a question about similarities between running Amazon and the Post, Bezos said, “We run Amazon and the Washington Post in a very similar way in terms of the basic approach. We attempt to be customer-centric, which in the case of the Post means reader-centric. I think you can get confused, you can be advertiser-centric — and what advertisers want, of course, is readers — and so you should be simple-minded about that and you should be focused on readers. If you can focus on readers advertisers will come.”

You can’t shrink your way to relevance. When he took over, Bezos said, the Post already had an “outstanding” tech team and newsroom, and a top-notch editorial leader in Marty Baron. But the newsroom kept eliminating people, which wasn’t working.

“What they needed was a little bit of runway and the encouragement to experiment, and to stop shrinking. You can’t shrink your way into relevance.” Since then, the paper has added about 140 reporters and significantly grown the tech team — and it’s worked.

“We’ve grown our way into profitability instead of shrinking our way into profitability.”

Don’t look for a patron or expect charity. Bezos was adamant that the Post should be run as a profit-making business, and that news organizations shouldn’t hold out for rich patrons who are willing to lose money indefinitely.

“This is not a philanthropic endeavor. For me, I really believe, a healthy newspaper that has an independent newsroom should be self-sustaining. And I think it’s achievable. And we’ve achieved it.”

Part of the reason, he said, is that “constraints drive creativity. The worst thing I could’ve done for the Post, I believe, is to have said don’t worry about revenue, whatever you need, just do the job. Because I don’t think that would lead to as much quality when there are in fact constraints.”

He also noted that whining about the internet and the death of the old business models won’t help anything.

“One of the first rules of business is complaining is not a strategy. You have to work with the world as you find it, not as you would have it be.”

Use technology, but don’t be a slave to it. One thing the Post has done is create a publishing platform called Arc, which it’s selling to other papers including the Los Angeles Times and Chicago Tribune. They also use data to do things like test headlines and understand how engaged readers are with particular stories.

But he warned there has to be a balance: “I would never let anybody or ask anybody to be slavish to data, but I’d also be super skeptical of people who aren’t curious about the data.” He also noted that for data to really be useful, it has to be “real time,” not delivered a day later.

Advertising alone will not support investigative journalism. Bezos thinks the current online ad landscape is incompatible with the kind of journalism the Post wants to do. He had particularly harsh words for programmatic advertising, in which publishers turn to an array of competing advertising networks to sell ads against specific audience segments.

“If you really wanted to build a business you could support with advertising alone, especially programmatic advertising, you’d have to be incredibly lean, you’d have to eliminate a lot of layers of editing, you would not do much original material, you would cleverly rewrite other people’s material, you would emphasize clever writing as opposed to original sourcing,” he said. “If you want to do investigative reporting and other kinds of very expensive reporting, you have to have a model where people will pay you for it.”

Once the Post started asking people to pay, they happily did, Bezos said. And they continue to do so.

“This industry spent 20 years teaching everyone in the world that news should be free. The truth is, readers are smarter than that. They know high-quality journalism is expensive to produce, and they are willing to pay for it but you have to ask them. We’ve tightened our paywall, and every time we’ve tightened our paywall, subscriptions go up.”

“Democracy dies in darkness.” Before introducing its infamous tagline in the wake of President Trump’s election, the Post worked on it for more than a year trying to make it sound a little less…dark. But they couldn’t figure out a way.

“We wanted a positive version of ‘democracy dies in darkness,’ and literally we had some of the smartest writers in the world try to invert ‘democracy dies in darkness’ to get a positive version of it, and we couldn’t do it, so we said to hell with it.”

His final advice: “When you’re writing, be riveting, be right, and ask people to pay. They will pay.”