Japanese carrier NTT DoCoMo sustained a record loss of 66,800 subscribers for the month of September, with the drop attributed to a lack of stock of the new iPhone 5s, reports Reuters. Rival Japanese carriers Softbank and KDDI saw gains of 270,700 and 232,700 subscribers respectively, according to Bloomberg, with all three carriers offering the iPhone 5s free on contract through special promotions.DoCoMo attributed the subscriber loss to customers who delayed purchases
