One challenge big companies face is the constant need to find ways to get even bigger.

Scott Galloway, professor of marketing at the Stern School of Business at New York University, led off this year’s Emerson Group Industry Day event with a presentation that touched on how disruptive it can be when big companies make big bets in order to keep growing their revenue.

Apple Inc., once a niche computer company, became a dominant maker of mobile phones, then expanded into watches and other wearables, and is now eyeing the electric vehicle market. More worrying for retailers, and particularly pharmacy and health chains, Galloway recounted how Amazon, which went from being an online book retailer to the “everything store” with its own brick-and-mortar outlets, is now arguably poised to become a disruptive health care company.

“They are clearly putting all the pieces in place to take health care from a defensive, on-our-heels industry to an offensive, on-our-toes industry,” he remarked. “Watch out health care: Here comes Amazon.”

This creative disruption in pursuit of growth is nothing new for retailers. Walmart didn’t wait until it was the leading general merchandise retailer in the United States to start looking for new growth opportunities, which it found by adding groceries to its stores and venturing into overseas markets. Walmart is making its own big bets on health care.

Now Dollar General is showing that it too is ready to make big moves to keep the wheels of growth turning.

The retailer has been a growth juggernaut in recent years, rolling out its flagship format at a pace of about 1,000 new stores a year. Coresight Research noted earlier this year that nearly one of every three retail stores opening in the United States is a Dollar General.

DG says it still sees plenty of room to keep expanding with its traditional format, and it too has added food to its mix and is positioning itself to be a health destination. But Dollar General is lining up new avenues of growth as well. The retailer recently said it will open its first 10 stores in Mexico next year, and it plans to operate 1,000 of its suburban pOpshelf stores — a format that debuted only last year — by 2025.

It’s a safe bet that the company is already thinking about what comes next.