When In-N-Out Burger made its way to Texas, it was explosive -- and a slam dunk for the California chain.
Lines of cars, mobs of people crowded the entrances in what many described as a feeding frenzy.
In-N-Out's menu is classic fast food -- burgers, fries, drinks and shakes. But you won't find a freezer or microwave on the premises.
All beef and produce is delivered and hand-cut daily. But there are secrets behind all the success.
Ray Maldonado, who oversees all of North Texas' In-N-Out Burgers, has been with the company for 43 years.
He started at 16 years old, peeling potatoes. He knows the company's secret formula -- but don't ask him to disclose it.
"It's stay true to who we are, which is what we have been able to do," he said. "It's staying true to our product. It is staying true to our people."
That business model started with Harry and Esther Snyder, who opened the first In-N-Out Burger in 1948 in Baldwin Park, Calif.
The menu they created is exactly the same as the one today.
After Harry Snyder's death, his son, Rich, took over, and the burger joint expanded further.
But in December of 1993, 41-year-old Rich Snyder was killed with two other In-N-Out executives in a horrific plane crash in Santa Ana, Calif.
The tragedy left only one heir -- Esther and Harry Snyder's granddaughter, 29-year-old Lynsi Martinez.
"She's one of us," Maldonado said. "She's just one of us."
She is also a bit of a mystery.
In a rare public appearance, Martinez showed up to the May opening of Texas' first In-N-Out Burger, Store 255 in Allen.
Budding journalist and soon-to-be Southern Methodist University graduate Brooks Powell snapped some of the few pictures in the public domain of Martinez.
"She was very unassuming when I approached her," Powell said. "She was not surrounded by a cadre of handlers; she was standing on the sidewalk, observing everything that was going on with the opening."
Recorder in hand, Powell started asking Martinez questions about the opening of In-N-Out in Texas.
"It's monumental, really," Martinez told her. "It is just huge. This is a landmark in our history, and since 1948, we've been doing things the same way. And to bring it to Texas -- it's huge for our whole In-N-Out family."
"I can tell you how much it meant to her," Maldonado said, pointing out a Texas T-shirt that Martinez personally designed.
Private is In-N-Out's mantra. It vows to never go public, never to franchise and never to share its profit statements with the public.
That secret -- estimated in the $200 million revenue range -- is locked up somewhere with the recipe for the company's "secret sauce."
Marketing experts such as Ed Fox, a professor at SMU, said such secrets lure customers.
"We talk about customers as evangelists -- customers who like what you do and they like your product and your service so much that they are ready to tell all their friends about it and anybody who they meet about it -- and In-N-Out Burger seems to have captured that kind of enthusiasm," he said.
What is next?
In-N-Out says to expect more of the same -- nothing more, nothing less.