The popularity of smartphones has driven customers at O2 Ireland, with a 40 per cent rise in the number using the devices in the year to the end of June.

The company, owned by Telefónica, said its postpay customer base increased by 12,000 in the six months, and by 29,000 over a 12-month period. O2's mobile broadband customer base also rose, gaining 20,000 over the year to 165,600. Mobile data revenue represents 40 per cent of its mobile service revenues. The company, owned by Telefónica, said its postpay customer base increased by 12,000 in the six months, and by 29,000 over a 12-month period. O2's mobile broadband customer base also rose, gaining 20,000 over the year to 165,600. Mobile data revenue represents 40 per cent of its mobile service revenues.