There are already way more mobile subscriptions than there are people in Australia (around 29 million vs just under 23 million), but population increases and a rapid growth of machine-to-machine (M2M) links using the mobile networks are among the factors that will see the total number of subscriptions rocket up to 35 million by 2015.

M2M represents a $300 million market opportunity for carriers according to Telsyte, but the company warns that the segment has a lower average revenue per user (ARPU).

"More than one-third of Australian businesses not currently using M2M applications are considering them, creating a huge opportunity for carriers, developers and value-added partners who can educate buyers and provide innovate approaches to service delivery," said Telsyte research director Foad Fadaghi.

Other considerations are the growing number of people with multiple mobile devices (typically a phone and a tablet), plans aimed at the 'BYO smartphone' segment, and increasing demand for subsidised smartphones.

Telsyte recently predicted that 90% of Australian mobiles will be smartphones in 2015 - that's 18.5 million handsets.