Yes, you can get 10,000 miles for every 4 "earned upgrades". In theory this is only for those who fly primarily internationally (80% international is the figure you hear quoted), but many have reported that this is not strictly enforced. Call Customer Service and tell them you want to "exchange upgrades for miles". If you meet resistance, just keep calling back until you get somebody who will do it. Generally, the process takes a few days, and you may see the upgrades subtracted from your account 2 or 3 days before the miles are added.