The [coca name='gold-delta-skymiles.Name' type='cards'], [coca name='platinum-delta-skymiles.Name' type='cards'] and [coca name='delta-reserve.Name' type='cards'] all offer one free checked bag per eligible flight. This is a potential savings of $60 per person round-trip. However, the free bag perk applies to up to nine companions on the same reservation. This makes it considerably more lucrative for big families or groups traveling on the same itinerary.