Amazon delivery services are likely to have been busy over the past few months, with the online retailer announcing a significant increase in sales during the second quarter of 2012.

The company revealed that net sales rose by 29 per cent year on year to $12.83 billion (£8.16 billion) during the period, compared to $9.91 billion in the corresponding quarter last year.

If the $272 million unfavourable impact of changes in foreign exchange rates had been taken into account, net sales would have risen by 32 per cent.

International sales - from Amazon's sites in the UK, Germany, Japan and other global markets - climbed 22 per cent year on year to $5.51 billion.

The company's operating income was $107 million during the second quarter of this year.

All of the retailer's top ten selling items were digital products, such as the Kindle e-reader, Kindle books and accessories.

The Kindle Fire, a tablet device that is currently only available in the US but is thought to be coming to the UK soon, remains the top-selling product available on Amazon.com.

Other recent developments in the company's digital offerings include the expansion of its Prime Instant Video service, which now provides access to more than 18,000 television episodes and movies, ranging from Forrest Gump to The Silence of the Lambs.

In a statement coinciding with the release of the second-quarter figures, Amazon founder and chief executive officer Jeff Bezos claimed that Prime membership with the retailer is "the best bargain in the history of shopping" and insisted the statement is "not hyperbole".

"Prime selection has grown to 15 million items. We've also added 18,000 movies and TV episodes available for unlimited streaming. And we've added the Kindle Owners' Lending Library - borrow 170,000 books for free with no due dates - it even includes all seven Harry Potter books," he said.

Author:  Adrian Medland