Most CEOs know that, if their workers are happy, they're also more productive. But how to make them happy is the challenge. Many take the goal too personally and try to build staff contentment through personal relationships. They get exhausted and find the strategy simply won't scale.

So what can you realistically pull off to make people happy at work?

Professional growth
People want to stretch, to develop their natural talents, feel their life has a narrative and is going somewhere. When they feel that they are growing, they may be exhausted but they're also inspired, energetic, and willing to take on a great deal. (That's one reason why investing in people can deliver a higher return that investing in new technology.) Anyone who reports to you (and anyone who reports to them) should have a professional development plan. That will keep everybody engaged, busy, and--eventually--happy.

Strong community
Everybody wants to be proud of where they work, to feel that they are investing the most precious thing they have--time--in something that matters. For some companies, the mission or the products are enough. If you make things that cure disease, create cleaner air, save carbon emissions, or improve life in any way, your business has an intrinsic sense of purpose which is probably what drew people to it in the first place. If you make ball bearings, knowledge-management software, light switches, or other kinds of widgets, you may find it tougher to demonstrate how you make the world a better place. Superficial social-responsibility projects won't fill this gap for you. You need to create direct links between the success of the business and the community you serve. These need to involve the entire work force and should be active, public, visible, and long lasting. Many companies get their staff to choose the causes or charities they support. The more they're engaged in these commitments, the more meaningful they will be to them--and your company community.

Fair treatment
"Everybody here is somebody." That's how one call-center rep once explained to me why he loved the company where he worked. The job wasn't thrilling, the pay wasn't great, but every single person was treated with love and respect. Just walking through the door, he said, made you glad to come to work. When people got sick, co-workers worried. When someone was due to retire, she most likely came back to work part time, just for the camaraderie. Sooner or later, everyone in a company like this talks about it as being like "family." The CEO knows everyone's name--even the names of everyone's kids and pets. This kind of fair--and kind--treatment also means startlingly low turnover rates, which also saves money. But it's not really about the money.

The very best companies I've studied and written about honor these principles and enact them lavishly. They don't pay lip service, and they don't do the bare minimum; they go overboard. Their CEOs do so because they know the secret of leadership: Look after the people, and the people look after the business.