Earlier this year, Amazon threatened to cut US Postal Service deliveries by as much as two thirds . Now, the parties have reached tentative a deal that will see USPS deliveries reduced by 20 percent, The Wall Street Journal reported. While not as drastic as first menaced, the reduced volume will still deal a financial blow to the USPS. "We’re pleased to have reached a new agreement with USPS that furthers our longstanding partnership and will let us continue supporting our customers and communities together," an Amazon spokesperson told the WSJ .  Amazon is the USPS's largest customer, accounting for 15 percent of its volume and $6 billion in revenue. A two-thirds cut would have been a disaster for the USPS, but a 20 percent reduction could result in more than $1 billion in lost revenue nonetheless.…