DoCoMo's addition of Apple iPhone 5S and 5C models to its wide range of smartphones did not bring the best results as the carrier had expected, in fact the company reported a loss of 66,800 net users in September.

Is it a move that went bad for DoCoMo? At least this is what Japan's largest mobile phone carrier wants to believe. Despite adding Apple iPhone 5S and 5C models to its smartphone lineup in order to regain  lost market share from SoftBank and KDDI, DoCoMo has reported a loss of 66,800 net users in September. Also, the carrier blamed the record monthly drop in mobile subscriptions to limited stock of new iPhone devices.

The limited stock of iPhones was seen as  good business for rivals KDDI and SoftBank, who long enjoyed the sale of Apple devices through their networks. However, that ended in September when DoCoMo introduced Apple's two latest smartphones, the 5S and 5C, to its smartphone lineup. An earlier study suggested that two-thirds of DoCoMo's lost subscribers chose rival carriers just to buy an iPhone. Considering that, it was a smart business move for DoCoMo as well as Apple. However, the limited supply of the iPhone devices turned out to be a greater loss for the carrier than not having Apple smartphones at all.

It would be too early to conclude that DoCoMo made a wrong decision in adding iPhones to its lineup. Apple iPhone 5S sees a huge demand worldwide and had a record opening with more than 9 million units sold during the launch weekend. Good demand is always good for business, provided there is ample supply. DoCoMo has learnt that the new iPhone can be a decision maker in carrier choice and hence KDDI and SoftBank benefitted with their ample supply, Reuters reported.

Last month, DoCoMo had a total 61.8 million subscribers, while KDDI had 39 million and SoftBank 34 million. Although the rival carriers are behind, its is essential that the network maintains a consistency in fulfilling customers' desires before it loses more subscribers. On the other hand, SoftBank and KDDI are fast growing national carriers. Softbank had the largest share of iPhone sales in Japan with 39.5 percent, DoCoMo closed at 31.9 percent and KDDI covered 28.6 percent, Bloomberg reports.