His point: no matter how loudly the wireless carriers talk about G-level speeds, do consumers understand or care about 4G vs. 3G? He suggested that maybe they don't. “For all the money we have spent, what does 4G mean,” asked Malloy.

The next speaker, Tom Bedecarre, chairman of digital marketing agency AKQA, flatly warned: “Millennials are burned out on advertising.” Doing more of it, harder, is not the cure, he suggested.

Bedecarre also warned: “If you are not on mobile you will be left behind. It's a monster.”

Gibu Thomas, a senior vice president at Walmart, said: “Consumers don't care about channels. They care about convenience and saving money.” His further claim: Walmart is seeing strong adoption of its mobile apps but the heaviest apps users also are heavy in-store customers, that is, the channels are not exclusionary.

Use mobile to bring enhanced personalization to retail and customers will applaud it, suggested Thomas, who added that over 50% of Walmart shoppers already own smartphones.

On another panel, Gokul Rajaram, product engineering lead at payments innovator Square, warned: “You have to be everywhere today because your customers are everywhere.”

Meantime, when it came to the future of MCX, the Merchant Customer Exchange payments innovation spearheaded by Walmart, senior executive Dodd Roberts said that the present payments processing system is antiquated, that it arose in a time when actual paper slips were imprinted with card data at retail point of sale, and it is high time for innovations that lower costs and increase security for all parties.

He also insisted that MCX is a very real entity that, soon enough, will be in the hands of many consumers.

Bottom line from the Open Mobile Summit speakers: huge changes are coming, fast, and at the center will be the mobile device, a tiny computer more and more of us take with us everywhere.