For the curious, each head and pair of hands have a unique network of tiny blood vessels. Using an algorithm and specialized devices, thermal scanning can record the information much like a fingerprint.
Obvious advantages include eliminating the need for an additional item to carry around and potentially lose. It is also hard to imagine the face and hands getting stolen and used for unauthorized transaction as opposed to, say, fingerprints which have been hacked in the past.
The face pay technology will help the company reach its steep target of $2 billion annual sales.