Google's relationship with television is spotty, at best. Google TV, whether as a set-top box or as a built-in product, has been an ongoing punchline. It didn't even sell television shows in the Play Store until a year ago. But Chromecast is different. It's Google's cross-platform answer to AirPlay, a video-friendly dongle that fits snuggly behind your TV. And, most importantly, they're practically giving it away.