In the first three quarters of 2014, the Google Chromecast and Amazon Fire TV made stunning gains in sales activity versus the market-leading Roku and the No. 2 device from 2012 and 2013, the Apple TV. Roku snapped up 29 percent of sales, while Google Chromecast rose to claim 20 percent, edging past the Apple TV's 17 percent. The Amazon Fire TV, which launched in April, is already in fourth place.