The 4.8-in.size of the device's screen was an attention getter. The wildly popular iPhone has a 3.5-in. screen, but there are reports that screen will be 4 inches for the iPhone 5 due later this year.
"In the U.S., larger screens are certainly a must-have," said Carolina Milanesi, an analyst at Gartner. "Vendors are going larger to differentiate ... We are getting to the point where we are reaching the physical limit before smartphones become more like tablets. "
Samsung also makes the Galaxy Note, a 5.3-in. smartphone sold by AT&T for its LTE network.
Milanesi said the Samsung line of phones represent "the only credible contender to Apple." Samsung is a "brand set apart from the likes of HTC and LG," she added.
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