Will the iPad be a success?

The figure included pre-ordered iPads, retail and channel sales. This is also just the Wi-Fi version, with 3G-capable devices expected next month.

Sales compare well with the original iPhone launch, and the number is impressive, but it is still to be seen whether the device will be a success, asking the question of whether consumers will be willing to pay for something fitting between being a mobile and a netbook.

"The launch went pretty much as expected; it was well received," said Shannon Cross of Cross Research to Reuters. "There is widespread enthusiasm for the product, but it's a new category, and it will take time for people to understand it."

But apps may be the real cash cow, with Apple saying that more than 1 million applications were downloaded from the company’s app store and more than 250,00 eBooks during the first day.

But it will soon face competition, with heavyweights HP and Dell bringing out similar rival devices. The iPhone and iPod of course have been huge successes, so the iPad has a lot to live up to.