Zappos employee Steven Weinstein, shown here in the retailer's Las Vegas headquarters, holds the record for longest Zappos customer-service call. Zappos

A Zappos employee recently had a customer-service call that lasted 10 hours, 43 minutes, breaking an internal record at the Amazon-owned online retailer.

On June 11, in Zappos' Las Vegas headquarters, Steven Weinstein answered a call from a customer who needed some help with an order of a few items. The two began to chat, and even after she was helped, she stayed on the line.

"It was excellent, the connection was amazing, and even though I never spoke to this customer before in my life I felt like I knew her for 15 or 20 years," Weinstein told Business Insider in an email. "It was just natural and time was flowing — it felt like it was effortless."

Weinstein said he took only one break during the nearly 11-hour period, about 2 1/2 hours in, to go to the bathroom. One of his colleagues brought him food and water during the call.

Zappos is an online store that sells shoes and apparel, which on its own isn't very exciting. That's why Tony Hsieh, who has led the company as CEO since 2000, decided from the beginning to make customer service the company's main product. The thinking was that customers could buy shoes anywhere, but they would become loyal to an online store if it went the extra mile to please them.

Hsieh's guidance resulted in an obsession with pleasing the customer, and call-center employees were encouraged to stay on the line for as long as necessary. Another of Hsieh's tenets is to "create fun and a little weirdness," and when employees combined this with customer service it resulted in employees going on marathon calls.

At Zappos, call-center employees are trained to use interactions with customers as a way to build relationships, not make a sale. And if a call is going long during a particularly busy time, then it's up to the employee overseeing the call center to assign more people to calls rather than to encourage an employee to end a call early.

The record that Weinstein broke was set by Mary Tennant in 2012 at nine hours, 37 minutes. Weinstein said he didn't stay on the line for so long "just for the sake of breaking" the record — he wanted to impress his customer.

"The connection was so strong that we could have talked for 18 hours if we really wanted," he said.