Verizon Wireless leaped forward in the race for online allure Monday by launching same-day delivery of phones to customers in the Philadelphia area, a perk the company said it would extend to several other markets by the year's end.

No longer will customers in Philadelphia and some of its suburbs have to wait overnight for new, replacement or even "loaner" travel phones. Now, orders made online by 10 a.m. will be delivered by 7 p.m. to the customer's location unless a particular device is on back order, such as the iPhone 5S and iPhone 5C, Verizon Wireless said.

The cost for same-day service: $19.99, compared to $14.99 for overnight delivery, which was previously the fastest service.

Orders must be placed at www.verizonwireless.com to qualify, and a signature is required upon drop-off.

The move reflects a retail marketplace so fast-changing and competitive that merchants are rushing to deliver online, and faster than ever, whether customers truly "need" it or not.

Verizon Wireless is investing in the new perk partly for how it plays with younger, tech-savvy consumers 18-34 years old with six-figure incomes. That subset of millennials, according to market research, are 56 percent more likely than the average online shopper to opt for online delivery, said Paul Macchia, a spokesman for Verizon Wireless in Basking Ridge, N.J.

Delivering so rapidly, however, does not come cheaply. If a company warehouse is close to consumers, and inventory can additionally be drawn from a network of nearby stores, it becomes less cost-prohibitive for retailers.

"It's very expensive to go that last mile," said Barbara Kahn, director of the Baker Retailing Center at the University of Pennsylvania's Wharton School.

In becoming the first wireless carrier to offer same-day delivery, Verizon will fill orders in Philadelphia and some of its core suburban towns in southeastern Pennsylvania and southern New Jersey with inventory from a warehouse in Coatesville, Pa.

As the program expands to Pittsburgh, New York, Dallas and San Francisco in the months ahead, the service may also draw from some of Verizon's 2,300 company-owned stores nationwide.

Speedy will not, however, ease the angst of customers whose phones are insured and in need of replacement because of, say, damage. In such cases, the company still urges customers to come to Verizon stores and discuss the situation. The online portal does not allow for that just yet, Macchia said.