The Chromecast is cheap. But even when something only costs $35, it's still nice to be able to cut that price in half. Okay, Groupon's offer isn't actually 50% off, but it's close. For the next five days (or until supplies run out), you can get a Chromecast for just $20.
These are refurbished units, but in the case of Google's streaming stick, that really doesn't matter. Even if it's scratched, it's going in the back of a TV where you will never see it again. Though I'm kind of curious how someone even goes about scratching a Chromecast in the first place. What were you doing back there?
Anyways, shipping is free. You can claim a dongle at the link below.