SingTel-Optus' release of Apple's iPhone 6 and 6 Plus smartphones was the most successful device launch in the company's history.

Optus postpaid marketing director Tim Cowan told Fairfax Media the telco had experienced its most successful week of sales on the back of the highly-anticipated device's launch in September.

"Clearly there's competitive pressure with the three big players in the market," he said. "The iPhone 6 period has really heightened that and the device has driven more demand than anyone would've really expected.

"We sold out of iPhone 6s and it exceeded our previous high, which happened with the launch of Apple's iPhone 5s."

Optus' experience is similar to that of Telstra, whose retail group executive Gordon Ballantyne told journalists in October that its iPhone 6 launch had recorded "significantly" better results than previous decides.

In both cases, the shortage of supply led to complaints from customers about wait-times for the new phone.

Morgan Stanley in September predicted the new iPhone 6 launch would shake up the market by giving Telstra an overall increase to its market share. Optus was due to stay flat with Vodafone Hutchison Australia losing a small percentage.

This would help deliver $300 million to $500 million extra mobile revenue for Telstra, the report said.

But Mr Cowan said the iPhone 6 had in fact provided a boost to the company's subscriber numbers overall.

The number of iPhone 6 devices in the market could also lead to an increase in the amount of data being consumed by customers because it can send and receive information at faster rates.

In November SingTel Singapore consumer chief executive Yuen Kuan Moon was asked by analysts about the effect Apple's iPhone 6 on the amount of data being downloaded, which in turn affects how much money the company can make.

"iPhone 6 is similar to the latest Samsung Note 4 [because] both are Cat 6 devices which mean … they can actually transmit data at a much faster speed," he said. "So we would expect users to eventually use more because of the better experience.

"It's still early days and it's only about two months since the phone was launched … but the initial trend tells us that we believe our customers who have bought these new phones are actually using a bit more data."

The author visited Singapore courtesy of Optus.