Coinstar's (NASDAQ:OUTR) Redbox kiosks are running away with the DVD rental business.

The automated retailer improved its market share by 7 percentage points, to reach nearly 50% of the market last quarter. And with DISH Network's (NASDAQ:DISH) Blockbuster still closing stores, and Netflix (NASDAQ:NFLX) continuing to push its customers into streaming, further gains appear to be in the cards for Coinstar.

In the video below, Fool contributor Demitrios Kalogeropoulos discusses Coinstar's growing dominance and argues that the company's biggest opportunity is in convincing its growing customer base to use the service more frequently.