Apple announced today that more than two million customers pre-ordered iPhone 5s in the first 24 hours after vendors opened up their order books on September 14. This is more than double the one million pre-orders received for the iPhone 4S in its first 24 hours last year.

The figure outstrips the first pre-order batch of iPhone 5s that will ship September 21, and though Apple claims the "majority" of pre-orders will be received on day one, a backlog already exists that will not be cleared until October.

Apple will be holding back additional stock for when its high street retail stores upon up their doors at 8 a.m. on Friday. Apple sold 4 million iPhone 4S handsets in the three days following its launch last year. Should iPhone 5 match that performance at retail, it will be well on course to match the widely-reported prediction of Piper Jaffray's wonderfully-named Gene Munster, that Apple will shift 10 million iPhone 5s in its first three weeks.

Only time will tell if the iPhone 5 will stand up to the more lofty, and also widely-reported, premonitions of Craig Berger at FBR Capital Markets, who reckons Apple could move a staggering 250 million iPhone 5s over the course of its lifetime—a figure which depends on unprecedented levels of upgrade-frenzy among existing Apple customers, as well as a launch in mainland China. To put that into perspective, that would be more iPhones (across all models) than Apple has sold internationally since 2007. It's even been suggested that iPhone 5 could eventually help to push Apple's share price into four figures, and have an appreciable impact on America's GDP.

Sources: Apple, LA Times, The Inquisitr, Infopackets, Statista