Domino's (NYSE:DPZ) hasn't given shareholders much to worry about in the past few years as the chain soaked up market share in the key U.S. geography and expanded its footprint both at home and internationally. In fact, in closing fiscal 2018, the chain is likely to report its 31st consecutive quarter of sales growth in the U.S. -- and the 100th straight improvement in outside markets.

Investors will be looking for more impressive gains along these lines when Domino's reports fourth-quarter earnings on Thursday, Feb. 21. They'll be keeping a close eye on a few potential red flags, too.

A pizza

Image source: Getty Images.

Growth updates

Every national fast-food chain is eyeing the delivery business these days, but Domino's has shown that it maintains serious competitive advantages in this booming niche. Its value pricing and quick, efficient ordering process helped sales growth at existing U.S. stores land at 6.3% in the fiscal third quarter, while Papa John's sales dove by 10%. Domino's comfortably outpaced nearly all peers in the wider industry, including McDonald's and Starbucks, through the year.

However, the pizza giant has now logged three consecutive quarters of decelerating growth at home, so investors are eager to see that trend stabilize. The international business is slowing down, too, but not yet to the point that shareholders need to worry over potential market-share losses. In any case, look for Domino's to report healthy customer traffic growth to help it stand out in comparison to most casual-dining restaurant chains.

Check out the latest Domino's earnings call transcript.

Strategic initiatives

CEO Rich Allison and his executive team have charted a risky path toward future growth that relies on the company adding lots of locations to neighborhoods it already serves well. Management calls the approach "fortressing," and they admit it is bound to pressure comparable-store sales as new restaurants poach revenue from existing shops.

The move will reduce customer wait times, though, and should support the broader strength of the business by lifting overall sales in the short term while delivering more profit for franchisees and investors over the long term. We'll get an update on Thursday on how well this strategy is playing out so far.

Looking ahead

Domino's doesn't issue sales or profit forecasts, so investors will have to estimate for themselves where growth might end up in 2019. But the chain did recently affirm its medium-term outlook, which predicts sales growth of between 3% and 6% at existing locations. Coupled with annual store footprint gains of around 7%, that should translate into about 10% higher revenue per year. Domino's might see profitability decline slightly as food costs rise, but its efficient operating model should ensure plenty of earnings growth.

Looking further out, the company has ambitions to operate as many as 25,000 global locations by the year 2025 compared to about 15,000 today. Hitting that goal would require that the chain stretch its market share dominance through the next several fiscal years even as global peers like McDonald's and Starbucks pour billions into boosting their home-delivery capabilities. That's a tall order, but the good news for shareholders is that Domino's enters this fight as the clear leader in this quickly growing industry space.