Google Intros $35 Streaming Video/Music TV Stick

LittleBill wrote:
50 foot hdmi cable is 16 bucks, this is essentially what this does minus the wire

Essentially, yes. But with Chromecast, once the streaming has started you can now use your device to do something else whereas with the HDMI cable your device has to be tethered via the hdmi cable the whole time. This also allows devices that don't have an hdmi output (such as my 1st gen Nexus 7) to be used to stream content.