BENTONVILLE, Arkansas: The world's biggest retailer, Wal-Mart Stores, is expanding its grocery home delivery service. Online customers of its Sam's Club warehouse membership scheme can order a wider range of non-perishable products for direct delivery to home or business.

Wal-Mart has adopted the same business model as online retail giant Amazon, which began grocery deliveries last year.

Sam's Club, which now offers items such as Perrier water, Kellogg's snack bars and washing-up liquid, claims to be cheaper than Amazon, although its product choices are narrower.

US retailers and consumers have been slow to adopt grocery home deliveries. In the UK and mainland Europe, however, delivery to the front door is becoming increasingly popular.

Amazon is currently trialling such a service in its home town of Seattle.

Data sourced from Financial Times online; additional content by WARC staff