What people expect matters a whole lot. A man with a summer home in Florence and a luxurious bed can be unhappy while a monk without a home or even a pillow can be content. What we expect has a great deal to do with how we react to the world.

So the evolution of customer expectations has a big impact on how business is done. The interface between customers and business has changed dramatically over time, and with it has come new expectations.

There was a time when business was largely a personal affair between shop owner and customer, and these customers expected satisfaction or a resolution from the person who sold them the goods.

But as business got bigger, the relationship between customer and business changed—and with it, what the customer expected from the business in terms of customer interaction.

At first store owners were still responsible for the products they sold, and then customers expected the companies themselves to take responsibility and warranty for the goods sold. This meant correspondence and a toll-free number where customers could reach someone at the company.

Over time, as we know, written correspondence through the mail disappeared and the contact center became the norm and the expectation. If the business was good, the call would reach a knowledgeable agent immediately. If the business was bad, there would be a long wait time and a less experienced agent. After that came the customer expectation that calls would be handled by an outsourced firm, and a company with poor customer service would have no American agents or maybe not even agents at all—just an interactive voice response system or a Web site to use for support.

But the pendulum is swinging back to more robust support in the minds of many customers now that technology once again makes the personal touch possible.

Telephone support alone is not enough, especially for those raised with the Internet. Just as customers now can text, chat, talk over social networks, e-mail or call their friends and family, they are growing to expect that they can reach businesses this way, too.

Those businesses that embrace this new multichannel reality will win the customer experience battle. A business that clings to telephone support and perhaps e-mail or a self-serve Web site is scraping by as a dinosaur of the past and not meeting modern customer expectations. To have trouble with a business and not be able to reach out easily from a smartphone can disappoint and inhibit customers from the contact they need.

So just as businesses 40 years ago suffered when they did not have a customer helpline with a toll-free number, so today do businesses not live up to customer expectations when there is no way to reach a company by social network, no way to interface via mobile app, no self-serve option that can be combined with chat and interactive support.

The customer service landscape is a very different one from what it was even 10 years ago. We can thank technology—and we can thank changing customer expectations.