Survivors of the Valentine's Day school shooting in Parkland, Florida demanded change from their lawmakers, but a swifter response seems to come from private companies.

Dick's Sporting Goods announced through tweets Wednesday that their chain of stores will no longer sell assault style firearms and would raise the minimum age to purchase any firearm from 18 to 21.

Hours later, Walmart announced a similar gun policy change, which also raises the minimum age to purchase firearms and ammunition to 21, as well as stop the sale of toys resembling assault rifles.

Paul Fadil, professor at the University of North Florida's College of Business, said companies in the past have made public changes following tragedies, but the reaction to Parkland is starkly different.

"One thing people forget is Dick's banned assault rifles after Sandy Hook, but then they went back to selling them," Fadil said. "The difference is those parents [of Sandy Hook victims and survivors] didn't have one one-thousandth of what [Parkland] kids today have in social media presence."

Dick's Sporting Goods pulled assault-style rifles after Sandy Hook, too. It didn't last.

Fadil, who chairs the Department of Business Management, said he believes CEOs are taking a hard look at who their stakeholders and customers are and making decisions that will protect profits.

"The soccer mom who comes in to buy a uniform for her kids all of a sudden now has jumped an individual who comes in to buy an AR-15 rifle," Fadil said.

He expects other companies to mimic the sporting goods shop and predicts the effects will be more long lasting.

Dick's CEO Ed Stack told NBC News their new policy won't waver.

"We don't want to be a part of the story any longer," Stack said. "If these kids can be brave enough to do this we should be brave enough to make a stand ourselves."