The first two died within 30 days, the second one took about 4 months I think. Not a huge sample size, but it kind of matches the typical hard drive failure bathtub curve.

I just double checked, and mine were actually from a similar seller on Amazon - they all seem to be from the same supplier though - the warranty card and packaging are identical. So ymmv?

Warranty was easy, I emailed the email address included in the warranty slip, gave details on order number + drive serial number, and they sent me a mailing slip within 1 business day. Print that out, put the drive back in the box it shipped with (I always save these), tape it up and drop it off for shipping. In my case, it was a refund of the purchase pretty much as soon as it was delivered to the seller.