(KUTV) Nicole Tanner started Swig with her husband, Todd Tanner.
They opened the first location in 2010, and the popularity of the shop's "dirty" Diet Cokes and cookies exploded.
There are now 18 Swig locations in Utah and Arizona.
Tanner and her husband love soda. They were living in St. George, Utah, without a job when they started brainstorming ideas for a business and ultimately came up with this drive-thru drink shop.
"We put everything we had into this concept," Tanner said. "We really believed it would work mainly because we would go there if we were a customer."
Many people thought they were crazy -- including themselves.
Even their own accountant was skeptical of the idea.
"He even told us years later, 'I gave you guys six months,'" Tanner recalled.
But Tanner believes the business was able to become successful through a lot of hard work.
"We were in that business day in, day out," she said.
The couple has five children, and Tanner was a stay-at-home mom at the time. The youngest child was five years old and had just started school.
"They had to share their mom and dad," Tanner said of her kids.
The original Swig was located on the property of a former skate park that later housed an insurance company.
The building's owner gave it to the Tanners for under the asking price.
"He said, 'You know what, I just want you crazy kids to succeed,'" Tanner told Shauna Lake.
After finding a spot, the Tanners had to figure out their menu. They started with basic flavors to add to fountain drinks, and then customers gave them ideas for more flavors and drink names.
And you can't forget the famous sugar cookie when talking about Swig.
The Tanners initially outsourced the cookies from Dutchman's Market in Santa Clara.
"The volume just took off really fast, where we had to get our own bakery," Tanner said.
Swig's 18 locations now sell thousands of drinks and cookies each day.
Tanner, who is often called the "Swig Lady," is humbled but amazed at Swig's success.
"I love customers," she said. "I love to meet our customers and know who's coming through our lines. I wish I could be in every store all the time and see our customers that we love so much."