Where is Amazon's same-day delivery service going next?

Amazon is expanding its same-day delivery service not just to all of Manhattan, but to other New York City boroughs as well, with unknown implications for the retail industry.

The e-commerce giant won't say, but it will say it has expanded its Prime Now same-day delivery service out of Manhattan for the first time and into select neighborhoods in Brooklyn.

The service allows Amazon Prime subscribers in neighborhoods such as Brooklyn Heights, Fort Greene and Prospect Heights to get free delivery on a limited selection of goods within two hours of ordering.

“We have been steadily adding Zip codes since we launched in December,” said Amazon spokesperson Kelly Cheeseman. “Manhattan customers love Prime Now and we are excited to expand soon to other boroughs.” The company also plans to offer the service in other metro areas, but would not name them.

Prime members pay $99 a year for two-day delivery on a large catalog of goods and can also stream music, movies and TV shows. Amazon caters to these members, which analysts estimate may number as many as 50 million worldwide, because they are believed to spend several times as much on Amazon in a year as non-members do.