This article originally appeared on LinkedIn.

Customer service was simpler in the era before big box chains and online shopping. Back then, to delight his clients, a business owner simply needed to offer fair prices, convenient hours and honest advice. To really make an impression, he might deliver a customer’s purchases to his home or ask the shopper about her children. He probably knew most of the families he served.

Best of all, business owners had an excellent, instant measure of success: A customer’s smiling face.

Many transactions today involve very little human contact. Consumers can buy just about anything they want on their phones (after browsing online reviews and price comparison sites first, of course) while waiting in line for their morning coffee. And if a customer doesn't like her latte, she may just dash off a complaint to the store’s Twitter feed instead of telling the barista. Or when shopping, if she’s not sure how a dress fits, rather than seeking honest advice from a sales clerk, she might post a photo on Instagram to get input from her friends.

While many things have changed, some important truths have not:

1. Good service makes people happy, regardless of whether you can actually see them smile. These days “smiles” come in different forms. They can be a “like” on Facebook, a positive review on Yelp or a glowing recommendation of a company’s services to a friend.
2. High-quality service doesn't have to cost a lot. Smart companies delight customers by automating routine tasks, but channeling some of the resulting cost savings into ensuring a human voice for complex transactions or requests. Companies that correctly identify these moments of truth for customers and serve them with a human touch win long-term loyalty.
3. Good service starts with knowing your customers. It may seem impossible for executives or employees of today’s global companies to know their thousands of clients the way small business owners once did. Yes, we live in more complicated times, but we also have technologies that can bring us closer to customers, faster. Companies organized around the Net Promoter System®, for example, collect instant feedback from customers and then rapidly share it with employees. It’s not as fast as a smile, but it’s close.

In fact, smiley faces are an important visual element in the Net Promoter System because a smiling face remains one of the most basic signs that you’re doing right by customers. When was the last time a company put a smile on your face?