The fast-casual pizza business is much like the pizzas they sell: Made quickly, and with a wide variety of flavors.

Consider the three biggest chains that have emerged so far as the largest in the burgeoning sub-sector, all of which turned up the heat on their growth and used vastly different strategies to do so.

Blaze Pizza. The Pasadena, Calif.-based chain that now has over 100 locations. It is growing quickly with an all-franchised business model and has sold out the rights to develop every territory in the U.S.

MOD Pizza. Thanks to the backing of $74 million in equity financing — and growing — the Bellevue, Wash.-based chain tripled in size last year to 92 locations, 80 of which are company-owned.

Pie Five Pizza Co. Started as an airport format by the buffet chain Pizza Inn, Pie Five now has more than 80 franchise and company locations, and continues to grow thanks to the cash generated by its parent company. The company expects to pass 100 units by June.

“There’s going to be room for a lot of different companies in the segment,” said Randy Gier, CEO of Pie Five parent company Rave Restaurant Group Inc. “If you look at sandwiches, for instance, there are a lot of companies. And they’re all different. Jimmy John’s is different from Potbelly, which is different from Firehouse Subs.”

Pie Five Pizza Co.

Fast-casual pizza is perhaps the fastest-growing sub-segment of the restaurant industry. The companies boast fast ovens that can cook pizzas in mere minutes, while employees make the pies in front of customers — giving customers the option to build their own.

The three largest are among several concepts jockeying for position in a bid to be the market leader.

The segment includes Pieology, which now has about 85 locations, as well as Pizza Studio and PizzaRev, both of which have more than 30 units. All told, the biggest players have opened up 175 locations in a short time. And many of these companies are prepping for even more growth this year.

Both MOD Pizza, and Blaze Pizza, plan to grow rapidly this year — MOD plans to add 100 locations this year, which would more than double its unit count. Blaze, which recently became the first chain to exceed $100 million in systemwide sales, expects its system to reach $185 million this year — a growth rate of nearly 85 percent.

Pie Five recently noted that its systemwide sales more than doubled in the company’s fiscal second quarter, which ended Dec. 27.

Blaze Pizza

The aggressiveness suggests a potential quick oversaturation of markets with fast-casual pizza concepts — and there’s some early evidence that could have started. Pie Five’s same-store sales in its second quarter fell 1.6 percent, though the company said it was lapping significant growth from a year ago.

Many other emerging segments ran into problems when a lot of players tried to grow quickly, such as frozen yogurt and better burger concepts.

Executives from the companies acknowledge that they’re competing in a tough market. “The last thing the world needs is another pizza chain,” MOD Pizza CEO Scott Svenson told Nation’s Restaurant News.