By Stephanie Mehta, Fortune executive editor

Eat or be eaten. Fail fast. Throw out the old playbook.

Those may sound like clichés, but they also happen to be the new rules of the road for companies trying to inject their companies with digital DNA, according to a panel of executives who spoke at Fortune’s Most Powerful Women London conference Monday evening.

Their message: Companies must move quickly and executives must be willing to take risks as their customers increasingly go online to make buying decisions, consume media, and complain about –or celebrate—their favorite brands. “We used to be able to talk about ideas, maybe put a toe in the water,” remarked Laura Lang, CEO of Time Inc. , Fortune’s parent. Corporations today don’t have the luxury of time.

The panelists generally agreed that the rise of social media and other online resources has been good for society—but companies now are facing a new world order. “The digital reality makes everything very transparent,” Kristin Skogen Lund, head of digital services for Norwegian telecom company Telnor.

“You don’t control the message anymore,” added Wendy Clark, senior vice president for Coca-Cola . Clark, who oversees integrated marketing efforts for the beverage company, said customers’ ability to quickly disseminate information, true or false, puts an additional onus on corporations to proactively communicate with consumers.

Employees, too, are communicating differently, and that’s changing the way work gets done—and who gets promoted. The smartest guy in the room isn’t necessarily the one who will get ahead. Clark suggested that “always on” employees are constantly sharing information—they don’t squirrel away knowledge as a way of making themselves more valuable to their organizations. “It’s not the orientation of the up-and-coming population,” she said.

Large companies will surely have to seek out nimble, entrepreneurial partners—Clark said Coke even takes warrants or equity stakes in some of its partner companies. Lang stressed the need to make sure such alliances and ventures are structured and managed in smart ways so not as to drive away all the founders or principals of the smaller company.

But all the executives agreed that when big companies get it right, they have the ability to make a big impact. Clark invoked her boss, Coke CEO Muhtar Kent, who espouses a strategy of “test, fail, learn and scale.”

Read more about the Fortune Most Powerful Women London event.