The popularity of the Kindle - a device that Amazon Marketplace sellers and users of parcel delivery services are likely to have seen strong demand for - has been highlighted by the online retailer's announcement that books exclusive to the e-reader have now been downloaded over 100 million times.

Amazon now has a catalogue of more than 180,000 Kindle-exclusive titles, nearly all of which are available for Prime members to borrow for free up to once a month, with no due dates.

The range includes Helen Bryan's War Brides, which has been bought or borrowed over 270,000 times and featured on the device's top ten bestseller list for the past eight weeks.

A Scattered Life, Easily Amused and The Long Way Home by Karen McQuestion are also among the most popular e-books only available for the Kindle, along with Ed McBain's long-running 87th Precinct series, which was recently released in digital format for the first time and has been purchased more than 250,000 times since December.

Russ Grandinetti, Amazon's vice president of Kindle content, said: "We have a huge library of books that are only available on Kindle and they're super popular - in less than a year they've been downloaded more than 100 million times.

"Exclusive books are another great benefit for Kindle readers and we're going to continue to work hard to make sure the Kindle ecosystem is the best in the world for our customers."

Amazon is extending the range of e-books available solely on its flagship product by giving authors the option of making their releases exclusive to the reader by joining the KDP Select programme.

People selling products online and using Amazon delivery services in Britain could soon benefit from the UK launch of the Kindle Fire, with reports suggesting the tablet could finally reach these shores in the autumn.

Author:  Adrian Medland