Demand for the Verizon iPhone is off to a strong start. So strong, in fact, that Verizon ran out of their initial pre-order supply in less than 24 hours. Visitors to Verizon’s iPhone page are now greeted with a message indicating that pre-orders for the device are no longer being processed.

Though the Verizon iPhone will be available in stores starting on February 10, pre-existing Verizon customers were able to pre-order the device starting on February 3rd. And though some pundits expressed skepticism that the iPhone on Verizon would be that big of a deal, it appears that the long-awaited CDMA iPhone is poised to shakeup the wireless industry yet again.

The affects of the iPhone arriving on Verizon have been discussed and debated at length. While some are anticipating a significant number of AT&T customers defecting for the greener pastures of Verizon, AT&T may have effectively minimized the potential for a mass departure by offering users early upgrade options when the iPhone 4 was released – thereby locking in a large number of users to a brand new 2-year contract. Moreover, AT&T recently stated that over 90% of current iPhone customers are still under contract, and paying a hefty early termination fee can’t be all that appealing.

Still, AT&T customers aren’t the happiest group of customers around. A Changewave survey taken this past December found that 15% of AT&T customers were planning to switch to a new carrier within the next 90 days whereas only 4% of Verizon customers indicated plans to switch. Compounding matters for AT&T is that dissatisfaction with poor reception and dropped calls only seems to be growing. Indeed, the common thread amongst all the recent iPhone 4 reviews has been how much greater the call quality and reception has been on Verizon measured against AT&T.

Moreover, AppleInsider recently got their hands on an internal corporate memo wherein Verizon Wireless strongly encouraged employees to hold off on picking up an iPhone 4 for themselves and for family members due to unprecedented demand for Apple’s iconic device. The iPhone 4 on Verizon is in many respects the same iPhone 4 that’s been out since this Summer. But with AT&T long being a sticking point for interested iPhone owners who were unable to pull the trigger, the iPhone landing on Verizon really is a huge deal. Selling out of their pre-order supply of iPhone 4’s in less than a day speaks volumes – even more so for a phone that’s essentially been out on the market for 7 months.