Phone rang for 1.5 seconds, no voicemail, upon calling back it's a computer trying to get you to claim "a free $100 gift card to a major retailer". I didn't try to claim the gift card.
Rang twice, then hung up. Often a sign of a scammer. Blocked the call...which essentially added it to my list of THOUSANDS of blocked calls. Meaningless since these people spoof their calls anyway.