"The fact that the iPhone 5 is doing as well as it is opposed to other phones is a tribute to Apple marketing," Gartner analyst Van Baker told AFP. "They are really good at this."
The analyst dismissed efforts by Apple adversary Samsung to poke fun at iPhone fanatics and the lack of innovative handset features in print and video ads.
"I had to laugh at the Samsung ads," Baker said. "It's hardware geeks throwing rocks at Apple; but Apple has a good sense of what is important to include and when."
Aspiring iPhone 5 owners started a queue outside the Apple store in Manhattan last week and similar vigils have begun outside the California company's shops at other spots around the world.
Apple said that it received more than two million orders for its new iPhone 5 in the 24 hours after it began pre-sales online on September 14.
"iPhone 5 pre-orders have shattered the previous record held by iPhone 4S and the customer response to iPhone 5 has been phenomenal," said Philip Schiller, Apple's senior vice president of worldwide marketing.
Apple unveiled the new version of its iconic smartphone at a San Francisco media event on September 12 and promised that it would be available in 100 countries by year's end.
The first customers are expected to get the device on Friday, but Apple has pushed the delivery date for new orders out several weeks due to fierce demand.
The notion iPhone 5 being tough to get was expected to spur more people to lay siege to stores for the hotly anticipated release.
The iPhone 5 will be available at Apple retail outlets, and for US customers through AT&T, Sprint, Verizon Wireless, Best Buy, RadioShack, Target, Walmart stores and other resellers.
Some analysts say Apple could sell 10 million units in the opening days and 50 million before the end of 2012.
Apple shares broke the $700 mark this week and stood at $701.60 in after-market trade on Wednesday.
The iPhone 5, with a bigger screen and slimmer body, was quickly branded by analysts as a sure hit.
Apple chief executive Tim Cook called the launch "the biggest thing to happen to iPhone since the iPhone."
The California company called the iPhone 5 "the thinnest smartphone in the world," with a glass and aluminum body that is 18 percent thinner and 20 percent lighter than iPhone 4S.
The new iPhone has a rich four-inch (10-centimeter) display prime for the red-hot smartphone market, in which screen size is a key factor for buyers.
The iPhone 5 will debut Friday in the United States, Canada, Britain, France, Germany, Australia, Hong Kong, Japan and Singapore.
Pricing for US customers will start at $199 with a two-year telecom service contract.
Apple earlier rolled out its new iOS 6 mobile gadget operating system with new features, including a custom mapping service branded a disappointment by some reviewers.
"Seems pretty clear the new Maps is going to be the biggest problem with iOS 6," Apple fan John Gruber wrote on his Daring Fireball blog.
"It'll be interesting to see how long it takes for Google to release a standalone Google Maps apps in the iOS App Store."
Apple's custom mapping program replaced Google Maps in the operating system.
An iPhone change with the potential to irk fans is a new "Lightning" connector to replace 30-pin connections, the piece that connects devices to computers, power outlets or docking stations.
Apple will sell adaptors for plugging new generation iPhone and iPod touch devices into accessories already owned, such as stereo speakers or car sound systems.
The big-screen iPhone 5 compatible with high-speed "LTE" telecom networks has been among the most keenly anticipated products in the tech world.
"Apple is meeting all expectations," analyst Baker said. "Everything was getting great reviews until they started rolling out iOS 6 today."
The US Federal Trade Commission warned that scammers were already seeking to cash in on iPhone mania, with emails offering a chance to get one.
"Don't reply, and don't click on links provided in the message," the FTC said. "Links can install malware on your computer and take you to spoof sites that look real but whose purpose is to steal your information."