Apple is expected to sell 28 million iPads in 2011

Global sales of the iPad are forecast to hit 28 million next year, with analysts also predicting Apple's device will be "the in-demand gadget" for shoppers this Christmas. J Um Maynard, an analyst with UBS, said the momentum the iPad had generated since its launch in April showed no signs of slowing, adding that his estimate of 28 million sales in 2011 "could still be conservative".

He predicted further revenue growth for Apple following the recent releases of updates to its iPhone and iPod devices.

"The company should have some of the most highly sought after products in the holiday quarter," Mr Maynard said. "Despite tough economic conditions, consumers remain willing to pay for innovation."

Dan Cryan, a senior analyst at Screen Digest, agreed: "It has all the signs of being an iPad Christmas this year. The device is going gangbusters and it doesn't show any signs of slowing." So far, Apple has sold 3.27 million iPads.

"Tablets in one form or another have been around for a while. But in its first quarter, the iPad has almost done more business than all the others put together for the past three years," Mr Cryan added.

In the run up to the launch of the iPad, questions were raised over whether consumers would embrace such a device. The sales figures have already dispelled such fears. Mr Cryan said customers liked the iPad because "it is an incredibly physically beautiful attractive device, very intuitive and easy to use. And, of course, the Apple marketing magic has helped the sales".

Mr Maynard added that iPad sales did not seem to have hit Apple Mac revenues, although added that the device "is adversely impacting the PC industry, specifically notebook PCs". His research note said that those who buy iPads were likely to delay buying or upgrading their existing PCs.

The success of the iPad has prompted a rush to market of rivals developing similar devices. Recently Samsung launched its Galaxy tablet, while BlackBerry has also confirmed it is looking into a similar device. "While competition within the tablet segment is likely to heat up in the coming quarters, we believe viable threats will be limited for some time," Mr Maynard said. According to figures compiled by Generator Research, iPad sales could be worth $17bn (£11bn) by 2014.

Apple also released the next generation of its smartphone in June. Sales of the iPhone 4 are "robust" Mr Maynard said, raising his forecasts to 52 million sales next year, up from his previous estimation of 47.2 million. "Demand will remain strong through the year, due in part to aggressive international launches, as Apple continues to ramp up production of the device."

The new line up of iPods "should bode well for sales during the holiday quarter as Apple has added some compelling features to the line," he said. This includes a multi-touch Nano and an iPod touch with cameras in the front and back which can make video calls. UBS predicts a slight quarter-on-quarter rise to 9.5 million units sold in the three months to September.