Just 1% of mobile subscribers consume half of the total data

Arieso’s research showed that a minority of users account for half of downloaded data. About 1 percent of high-use subscribers downloaded half of the data volumes.

Siri, the iPhone's voice-activated assistant, has prompted users of the iPhone 4S to use nearly twice as much data, compared with the handset's predecessor, pressuring network operators, according to Arieso.

"Voice is the ultimate human interface,'' said Arieso's chief technology officer, Michael Flanagan. "As you lower the barriers,'' consumers will use smartphone functions more, he said. Arieso, based in Atlanta, advises clients on how to manage wireless networks.

Apple added Siri, dubbed a virtual personal assistant, to its latest iPhone. With a few spoken words, the artificial-intelligence feature helps iPhone users schedule appointments, write text messages, or check the weather, for example.

This week, Verizon Wireless, the largest US carrier, said the number of iPhones it sold doubled to 4.2 million in the fourth quarter.

Arieso's research showed that a minority of users account for half of downloaded data. About 1 percent of high-use subscribers downloaded half of the data volumes.

"The hungry are getting hungrier,'' Flanagan said.