Apple and Google’s app stores have been fortresses of commerce. South Korea fired a cannonball.

When buying apps or making in-app purchases, you’re pretty much limited to either Apple or Google’s systems, and those companies are paid a commission of up to 30% on your purchase. South Korea this week passed a law that will force them to allow alternative payment systems — ending commissions when developers sell things directly. It comes as Apple and Google are under pressure from antitrust regulators around the world. Marketplace’s Jed Kim speaks with Nick Statt, a reporter at Protocol, who says South Korea’s law is a big deal for developers.