The e-commerce colossus said customers in more than 2,000 cities, towns and suburban areas can now choose to have orders from its speedy-shipment inventory of 90,000 items delivered in three hours. The charge is $4.99 for Amazon Prime members and $14.99 for nonmembers.

One-hour delivery slots are available in hundreds of places, including major metropolitan areas like Los Angeles, Chicago and Washington, and smaller cities such as Des Moines, Iowa and Boise, Idaho, the company said. Prime members will get charged $9.99 for the service, which costs nonmembers $19.99, Amazon said

The Seattle-based company said it started testing the express delivery service late last year and expanding it this month.

“We saw an opportunity to use our unique operational expertise and delivery network to help make customers’ lives a little easier while unlocking even more value for Prime members,” Udit Madan, senior vice president of worldwide operations at Amazon, said in a statement.

Amazon launched its Prime program in 2005, offering members free two-day delivery on a selection of 1 million items, primarily DVDs, CDs, and books. Prime members now have access to over 300 million items across 35 categories, and tens of millions of products are available for free same-day or next day deliveries.

The company has used robotics and artificial intelligence technology to speed up order fulfillment. Regionalizing its U.S. delivery network into eight areas also has helped reduce delivery times, Amazon said.

Amazon is testing an ultra-fast service for deliveries in 30 minutes or less. Amazon Now is available in various cities in India, Mexico and the United Arab Emirates and is being tested in several communities in the U.S. and the United Kingdom, according to the company.

Rival retailer Walmart has focused on faster deliveries too. The Bentonville, Arkansas-based company says it offers same-day deliveries in under three hours to 95% of the U.S. population, compared to 76% three years ago.