iPhone 4: 600,000 Bookings In One Day

Only yesterday they started pre-orders for iPhone 4 in the U.S. and some European countries, and today Apple states I have received over 600,000 bookings in one day.
Precisely for this request exceeded expectations, the company apologized for some malfunctions in the reservation system on-line: "Many customers have had to abandon the process frustrating: we apologize to anyone who has encountered difficulties,
hoping that we try again or visit an Apple Store or a store of its operator as soon as iPhone 4 will be available. "
Even the launch of the iPhone 3G there were similar problems, perhaps even more severe and prolonged.