EarthLink is investing an estimated $13.5 million to build out Philadelphia's Wi-Fi network. The company is also paying revenue-sharing fees to the nonprofit agency Wireless Philadelphia to support the city's efforts to provide low-cost Internet access for low-income users.

Will EarthLink recoup this investment? According to Thomas Cooper, general manager at EarthLink Municipal Networks in Philadelphia, the company is counting on signing up as many residential and business customers as possible.

"We have several interesting strategies to get us on the right path and to hit our penetration targets. There's going to be a large push for us in the Philadelphia marketplace this summer," Cooper says.

Cooper adds that the marketing message "revolves around how the service is used at home, but the added value is that it can be taken with you. It has mobile value. It can be used in almost all public and private spaces in the city."

Customers can sample the service without having to sign a long-term contract. EarthLink is offering a one-hour pass for $3.95, a one-day pass for $7.95 and a three-day pass for $17.95. One month of service is $19.99. The one- and three-day passes will target tourists and occasional visitors to the city from the suburbs.

According to Gartner analyst Phil Redman, the value of mobility may be limited to a small number of customers. "I don't think that's going to be enough differentiation," Redman says. "Not everyone cares about mobility in these markets. You also need to look at PC and notebook penetration in many inner cities, and that is rather low -- so basically EarthLink and incumbents are going after the same market with similar pricing."

Redman adds, "I think generally cities that target specific areas and zones for wireless coverage will be successful, and if they look at it more for adoption by small- and medium-size businesses, individuals and the municipal workforce at a low-price point, that it will be successful."

For Esme Voz, founder of MuniWireless, the question is more about what cities will use it for, beyond Internet access.

Click to see: Thomas Cooper, EarthLink