The Post's Hayley Tsukayama offers the latest on the newest round of iPhone products and software. (Sandi Moynihan and Hayley Tsukayama/The Washington Post)

Gadget lovers still can’t resist the iPhone’s seductive call, even amid a bevy of enticing lower-priced alternatives that offer similar features.

In a Monday announcement, Apple said it sold 9 million units of its top-of-the-line iPhone 5S and less-expensive iPhone 5C during the first three days they were available. That trounced the performance of last year’s model, the iPhone 5, which sold 5 million units in its opening weekend.

The company also said more than 200 million devices already have been switched to its latest mobile operating system. The software, called iOS 7, is the most radical makeover of Apple’s mobile operating system since the iPhone came out in 2007. Apple released iOS 7 as a free update Wednesday for iPhone models dating back to 2010, iPads dating back to 2011 and the last iPod Touch that came out last year.

The downloads of iOS 7 during the first five days of the software’s release roughly doubled the amount of installations after Apple release iOS 6 last year.

The iPhone 5S and 5C’s quick start surpassed analyst forecasts that predicted Apple would sell between 6 million and 8 million models during the first weekend.

“The demand for the new
iPhones has been incredible,” Apple chief executive Tim Cook said in a statement. As part of the company’s effort to drum up interest in its most profitable product, Cook made an early-morning appearance at an Apple store in Palo Alto, Calif., when the new iPhones first went on sale Friday.

Apple’s stock gained $23.23, or 5 percent, to close at $490.64 Monday.

Part of this weekend’s higher iPhone sales volume stemmed from Apple’s decision to make the latest models available on a broader scale than in past years. For the first time, the new iPhone went on sale in China at the same time that it launched in the United States.

Apple could have sold even more iPhones during the opening weekend if the company had been able to deliver more of the 5S model, which sells for $199 with a two-year wireless contract. A gold-colored model introduced with the 5S line was in extremely short supply, much to the frustration of many shoppers who waited in long lines Friday to buy one.

“We appreciate everyone’s patience and are working hard to build enough new iPhones for everyone,” Cook assured consumers in his Monday statement.

Apple didn’t provide individual sales figures for the 5C and 5S, but figures released by a mobile research and marketing firm indicated that the more expensive model has been far more popular.

Within the first two days of sales, Localytics found three times as many 5S models were being activated than the 5C, which sells for $99 with a two-year wireless contract, Apple’s lowest price yet for a new iPhone.

— Associated Press