New York CNN Business  — 

Domino’s is binging on new stores to boost sales. The pizza chain opened its 16,000th store Monday and has grown by nearly 50% over the past five years.

It still trails Pizza Hut, which has more than 18,000 locations. But Domino’s dwarfs rival Papa John’s, which has only about a third as many stores.

Domino’s (DPZ) has rapidly added stores — 4,800 since 2014 — and it has plans to add thousands more stores as the battle for pizza supremacy heats up. Despite promotions, investments in new technology and a marketing blitz, Domino’s (DPZ) sales have underwhelmed Wall Street investors in recent quarters.

Competition among Domino’s, Pizza Hut and Papa John’s is fierce, and the its worse-than-expected sales demonstrate how Domino’s is struggling to stay competitive.

Domino’s stock has fallen 16% over the past six months. By contrast, Papa John’s (PZZA) stock has fallen just 6% over the same period, despite all its scandals. Yum Brands (YUM), which owns KFC and Taco Bell in addition to Pizza Hut, is up 10% during the past six months.

To better compete, Domino’s announced another major American expansion last year, and plans to add another 2,350 stores in the United States by 2028. In anticipation of the expansion, the pizza company is investing between $115 million and $120 million in its supply chain.

Domino's 16,000th store is in a Buffalo suburb.

The 16,000th Domino’s is in Cheektowaga, New York, a suburb of Buffalo. The company will host a ribbon-cutting ceremony, and the franchise owner will present a $16,000 donation to the Cystic Fibrosis Foundation in honor of the 16,000th store.

“This is an incredible milestone for Domino’s, and I am beyond excited it is happening in Cheektowaga,” said Ritch Allison, Domino’s CEO, in a statement.

For perspective, 7-Eleven — the store with the largest global footprint — has more than 60,000 stores. McDonald’s has more than 37,000, and Starbucks has nearly 30,000.

Allan Erwin, owner of the Cheektowaga Domino’s franchise, began his Domino’s career in 1993 as a delivery driver. He purchased his first store in 1998 and now owns 37 franchises. Domino’s says more than 90% of US franchise owners started out as delivery drivers or pizza makers at the company.