Amazon has unveiled what some are calling Uber for last-mile delivery, after the fast-growing service that replaces traditional taxis with an app that links riders and drivers.

Flex would allow ordinary people to make $18 to $25 an hour delivering packages for Amazon using their car and a smartphone, as an independent contractor. 

Flex drivers (must be 21 years old) will deliver ultra-fast Amazon Prime Now packages. This program for paid Amazon Prime members promises deliveries as quickly as one hour for $8, or free for two hours or more. In the future, Flex drivers may deliver other types of Amazon packages as well, according to the website.

Initially launched in Seattle, the service will expand to Manhattan, Baltimore, Miami, Dallas, Austin, Chicago, Indianapolis, Atlanta and Portland.

Amazon says tens of thousands of items are available for delivery under Prime Now including, in Seattle, alcohol, reports The Wall Street Journal.

Amazon has had a significant impact on supply chains and the e-commerce industry in North America and Europe, with its focus on same-day delivery and its developing relationships with 3PL companies for last-mile delivery, according to a survey of third-party logistics provider CEOs, sponsored by Penske Logistics and released Monday.

On average, e-commerce now accounts for an average of 11.85% of North American 3PLs' revenue, and CEOs predict it will increase to 20.85% in three years.

The survey also noted that ride-sharing companies, most notably Uber, are believed to potentially pose a threat to aspects of the 3PL industry in the future by providing last-mile delivery services and taking business away from small-volume couriers.

One problem for this model, however, may be the independent contractor status of these drivers. There already are lawsuits against Uber, grocery delivery startup Instacart, Postmates and others over whether these workers were misclassified and should be entitled to back pay and benefits as employees rather than contractors.