They swapped their ad budget for a kindness budget?

“Do you need to lie down?” “Should I call a doctor?”

That’s probably what your client would say if you suggested he replace his entire ad budget with a budget for helping people, right?

Well, that’s what the apparel company “Life is Good” did. And here’s the really crazy part — it worked.

The brand started in 1994 with a couple hundred dollars and some t-shirt designs that featured life-affirming slogans like “Forecast: mostly sunny” and “Do what you like, like what you do.”

After six years of slow but steady growth, the founders decided to crank things up with a national ad campaign. But right before they pulled the trigger, they got a letter from two brothers who suffered from a serious illness but managed to keep a positive outlook thanks to their “Life is Good” shirts.

“What do you do when you get a letter like that?” said co-founder Bert Jacobs not long ago on cnbc.com. Here’s what he and his team did:

They canceled their ad campaign and used the money to sponsor a pumpkin festival for kids near their headquarters instead.

Inspired by the festival’s success, they then created “Life is Good Playmakers,” a public charity with the mission of helping kids “who face illness and violence by focusing on opportunities instead of obstacles.”

By 2005, sales had soared to $50 million. And then things really took off. “Life is Good” retail stores started hosting free concerts and kids play events. And the founders created a “Hub of Optimism” on the company website where families can share their stories of heartbreak and hope.

Today, sales have climbed well over $100 million. What’s the secret behind this incredible success story?

It’s simple. The world doesn’t need another company that makes high-quality t-shirts with upbeat slogans on them. We’ve already got plenty of that kind of stuff in our dresser drawers.

But a company that rallies people around the power of optimism and helps kids in need that also happens to make high-quality t-shirts with positive slogans on them — — well, who wouldn’t get behind that?