A Bloomberg News analysis revealed that there were racial disparities in the free same-day delivery service being offered by online retail giant Amazon. The company was not offering the service to minority communities across six major states, including New York and Chicago.

Amazon, however, was quick to respond to the analysis and the criticism from city representatives. The company promised to bring its Prime delivery service to the mostly black Roxbury neighborhood in Boston, after the criticism regarding the neighborhood's exclusion from the service.

The company has now also sent letters to officials that state the expansion of free same-day delivery to the Bronx, which is the only borough of New York City that was not included in the service, as well as to the South Side of Chicago.

According to Amazon, the expansion of the Prime delivery service depends on several factors, which include the distance of an area to a fulfillment center, the demand in an area, the number of Prime subscribers in an area, and the ability of partner carriers to deliver to an area up to 9 p.m. daily.

"We will continue expanding our delivery capabilities and are adding more ZIP codes rapidly," said Scott Stanzel, a spokesman for Amazon.

U.S. Representative Bobby Rush is among the pleased officials on Amazon's efforts.

"As I said on the floor of the U.S. House of Representatives last week, 'Black Americans' dollars are just as green as any other Americans' dollars,' and I am glad that Amazon.com recognizes that," Rush said.

In Chicago, 2.2 million people were serviced by Amazon's free same-day delivery, but the 472,000 residents of the predominantly black South Side previously did not enjoy the perk.

Ruben Diaz Jr., the president of the Bronx Borough, also wrote a letter to Amazon founder and CEO Jeff Bezos about the exclusion of the Bronx and some black neighborhoods in Queens, affecting constituents that are largely black and Hispanic.