Jalen Rose analyzes what it means that LeBron James' pizza franchise is opening a new location inside of the Staples Center. (0:59)

LeBron James and his business partners have turned another small investment into a fortune.

Sources told ESPN that an investment that James, his business partner Maverick Carter and financial adviser Paul Wachter of Main Street Advisors made for less than $1 million in 2012 in upstart fast-casual chain Blaze Pizza has turned into $25 million.

The valuation was confirmed when Blaze Pizza sold an undisclosed percentage of the company to private equity firm Brentwood Associates a few weeks ago that valued the company at around $250 million, sources said. James owns about 10 percent.

Including endorsement payments, which will trigger in the near future on an undisclosed sales target, James' stake in the business is worth $35 million to $40 million, according to sources. That doesn't include his partnership with restaurateur Larry Levy, who runs franchises in Miami and Chicago for him.

"LeBron and I have always been about finding companies that we truly believe in and putting real money into them," said Maverick Carter, right. George Pimentel/WireImage

James, along with most of those invested in Blaze Pizza, took some money off the table, but it is not known how much he pocketed from the deal.

Wachter was provided a look at the company through movie producer John Davis, who had invested in food businesses, including Wetzel's Pretzels. Rick Wetzel and his wife, Elise, were the ones who dreamed up the Blaze make-your-own-pizza concept in 2011.

"We don't typically advocate for our clients to invest in food businesses," Wachter said. "The risk-reward equation is not generally that great, and there's a lot of grinding and blocking and tackling, and it takes a while for a concept to go global."

But Wachter said he liked what he saw in the management team and was really impressed with the product.

So were James and Carter.

Having made approximately $30 million off a stake in Beats by Dre when the headphones company sold to Apple for $3 billion, the two were looking for the next big thing.

"LeBron and I have always been about finding companies that we truly believe in and putting real money into them," Carter said. "We're not talking putting in $15,000 or $20,000. It's real money plus the expertise, understanding and knowledge that we bring, as well as bringing LeBron's name and likeness to the product."

After the initial investment in 2012, James wasn't allowed to endorse Blaze Pizza, because he had a deal with McDonald's, but news that he was involved was huge, Rick Wetzel said.

"When he invested in us so early on, he established us as the market leader," Wetzel said. "He put a star on our forehead as a company that was legitimate."

In 2015, James and Carter, with three years and $14 million left on LeBron's McDonald's deal, had a decision to make.

"It was a great partnership with McDonald's, we did some great things on television," James said during an appearance on Carter's web series, "Kneading Dough." "The potential on what we could make if we just put the time and effort into it exceeded what McDonald's guaranteed me."

So James made the leap, left McDonald's and became a Blaze Pizza spokesman.

The value of James, who currently has 37 million Twitter followers and 32 million Instagram followers, was seen immediately.

"Every time LeBron tweets about Blaze, it's like a sonic boom," Elise Wetzel said. "It jump-starts the conversation with tens of millions of people in the U.S. and around the world and leads to a genuine interaction between people who know and love the brand and people who haven't heard of us."

A video filmed in April of James behind a Blaze Pizza counter dressed up undercover as "Ron" garnered millions of YouTube hits and much news coverage.

For James and Carter, the true upside of their investment might not be close to being realized. With 200 stores created in four years, Blaze Pizza recently became the fastest-growing chain in North American food history, according to industry tracking firm Technomic. The company has goals of hitting 1,000 stores and $1 billion in sales by 2022 and eventually an initial public offering, which will be the real cash-out moment.