The following is an excerpt from the new book, Extraordinary Experiences: What Great Retail and Restaurant Brands Do, by Denise Lee Yohn.

Nathaniel Ru had a problem. He and his partners, Jonathan Neman and Nicolas Jammet, had just opened a new location for their budding fast-casual restaurant chain sweetgreen in April 2009, but there were no customers. Less than two years out of business school and steeped in debt, the threesome could have panicked — but they decided to throw a party instead.

The trio put speakers on the sidewalk and blared music into the park across the street. Soon enough, the noise attracted customers, the restaurant started buzzing with energy, and the founders had created a block party celebrating food and music. Best of all, their ingenuity didn’t just solve their business problem; it actually jumpstarted the realization of the dream they had from the beginning.

Ru, Neman, and Jammet had always wanted to make a big impact. A blog post on sweetgreen’s website explains their founding philosophy: “In the food world, there used to be trade-offs, things that were considered mutually exclusive. Your business could be scalable but not sustainable. Your food could be delicious but not healthy. We believe it’s possible to bridge the gap.”

Passion Plus Purpose Produces a Sustainable Business

They designed sweetgreen to be a different kind of restaurant — and actually more than a restaurant. They intended “to create experiences where passion and purpose come together.”

That’s why in addition to serving up savory salads made of fresh, locally sourced ingredients in sustainably designed buildings, sweetgreen also now hosts an annual music and lifestyle festival called “sweetlife.” It also teaches thousands of elementary school students about healthy food every year and partners with other socially minded organizations to offer healthy living programs. It has become a respected change agent among restaurateurs in New York, politicians in Washington D.C., and investors in Silicon Valley. It has indeed created, “a movement for a new way of living,” as Neman has put it.

In other words, sweetgreen is making a positive impact in the world without having to “give back.” Like other great brands, it uses its core capabilities and brand power to inspire social change.

Great brands don’t simply make charitable donations to satisfy their sense of corporate responsibility; they’re not interested in participating in social causes because of the marketing messages they can generate by doing so. They know that consumers want companies to improve their lives and their communities. And customers who value authenticity and altruism want to purchase from businesses that share those values.

Moreover, great brands see themselves as on a mission. Outdoor outfitter Patagonia says its reason for being is “to use business to inspire and implement solutions to the environmental crisis.” Home furnishings retailer IKEA aims “to create a better everyday life for the many people.” And sweetgreen wants to democratize healthy eating and build a community committed to better living. “Healthy food shouldn’t just be for the top 1 percent,” Neman once told CNNMoney.com.

Making a Difference One Salad at a Time

The farm-to-table movement is so popular in today’s restaurants that it’s hard to imagine that a lack of options prompted sweetgreen’s founders to start the company in 2007. But back then, the three were Georgetown University students who had trouble finding healthy places to eat that were also “fun and easy.” So they designed their restaurant concept around fresh and healthy food, with most ingredients bought from local farmers and purveyors.

In the 29 stores operating at publication time in five East Coast states, the District of Columbia, and California, the menu at sweetgreen features salads, soups, and rice and grain bowls. Ingredients are sourced from more than 100 local farms and prepared fresh in the restaurants; menu items consist of nutrient-dense, in-season produce, and humanely-raised livestock.

The founders aim to change the entire restaurant paradigm. “The disruption in the industry that we want to create [is] a national restaurant brand that still sources locally and does things right,” Neman told CBSNews.

Yet, the company isn’t satisfied with merely serving alternatives to standard fast food fare. It also wants to help people become better consumers. Its “Meet the Farmer” videos, which educate people about the origins and quality of their meals, is one way sweetgreen practices its mantra, “Know where your food comes from.” A chalkboard in each restaurant also lists the local ingredients available and the farms they were sourced from.

The company reduces its impact on the environment by using compostable packaging and store design details and furniture made from reclaimed materials like bowling alley tables. It also purchases wind energy offset credits to power the stores.

It extended its sustainable business practices to the menu, offering a “wastED” salad created in partnership with Dan Barber of New York-based Blue Hill restaurant. The recipe uses foodstuffs, including cabbage cores and kale stems, that are ordinarily tossed out during the cooking prep process.

Service at sweetgreen is also distinctive. To fulfill its goal “to leave guests better off than we found them,” its order-filling process differs from that of many assembled-to-order restaurants. “We don’t just pass food down a line. We take your salad and move along with you. We’re interacting with you and trying to make you a little happier,” described Ryan Jackson, an employee at the Connecticut Avenue store in Washington, DC.

Moreover, the brand has a “sweet touch” philosophy in which servers are encouraged to make a customer’s day, whether by rushing to open the door for someone with their hands full or providing umbrellas on rainy days. As part of the company’s “random acts of sweetness” program, employees have been known to put a coupon on the windshield of a car with a parking ticket and deliver a free meal to a regular customer who tweeted about being sick.

Sweetgreen Makes a Difference without “Giving Back”

Some of these customer satisfaction efforts may seem small or even commonplace, but as a whole, they comprise an important part of the company’s total approach to improving people’s lives. They show how a business as transactional as a restaurant can make a difference through its day-to-day operations.

(Extraordinary Experiences: What Great Retail and Restaurant Brands Do profiles seven great retail and restaurant brands and shows how they earn customer love and loyalty by creatively designing and consistently delivering great retail customer experiences. Learn more at http://deniseleeyohn.com/extraordinary-experiences.)