"The epicenter has been Silicon Valley," Sharma said.

Smartphones are much more popular in the U.S. than globally, with 55 percent of all mobile devices sold being smartphones. The worldwide rate is 27 percent. In addition, because Apple's iOS and Google's Android started in the U.S., the app stores for those platforms are still weighted toward software that appeals to Americans, he said.

The way carriers sell services has also affected U.S. mobile data use. For example, consumers in other countries are more often on plans that limit the number of texts they can send and receive. So users in the Philippines and the Netherlands, for example, are finding it more economical to buy a data plan and send messages via Facebook and other social networking services, Sharma said. U.S. carriers have been moving toward plans with no limit on messages, and on Thursday, AT&T .

Meanwhile, U.S. carriers have been among the leaders in rolling out faster network technologies including mobile WiMax, HSPA+ (High-Speed Packet Access) and LTE. "From a network perspective, the U.S. has been ahead of major markets," Sharma said. Verizon said this week that its LTE network reaches a majority of the U.S. population.

Against the backdrop of a strong and growing mobile data business, Hewlett-Packard's decision on Thursday to was unfortunate, Sharma said. He thinks the company was trying to drop low-margin product lines but dropped WebOS too soon.