It took Verizon only two hours of having the iPhone 4 available for pre-order to break its all-time record for first day sales of a single device. That's in spite of the fact it only opened up pre-orders to its own subscribers and did so at the dead of night. To be clear, between 3AM and 5AM yesterday morning, more people ordered up the iPhone 4 than Verizon has been able to get through its doors on any full product launch day. Predictably, the carrier hasn't bothered to include the actual number of devices ordered up, but judging from the server issues it was having immediately after making the handset available and the subsequent shutdown of advance pre-orders, we'll go ahead and guess it was "a lot."
source: Verizon breaks first day sales record with iPhone 4 pre-orders -- in only two hours -- Engadget