Amazon expands same-day delivery, and makes it free

Amazon is upping the ante in the fulfillment wars by expanding its same-day delivery service for Prime members to more markets and making it free.

The company added two new markets, San Diego and Tampa Bay, to its list of same-day delivery areas while also reducing the price to free for orders over $35. The company already offers same-day delivery in several regions, including New York, Philadelphia, San Francisco, Seattle, Atlanta, Boston, Baltimore, Dallas-Ft. Worth, Indianapolis, Los Angeles, Phoenix, and Washington, D.C.

Previously, the cost to use this service was a flat $5.99 for Amazon Prime member. Meanwhile, non-members will continue to pay $8.99 when requesting same-day delivery.Orders, which can be placed seven days a week, have to be submitted by noon to be received by 9 PM that day.

Amazon's announcement comes within days of rival Walmart saying it plans to test a new unlimited online shipping service this summer for $50 per year, a move that may hurt Amazon.