For low-income Americans, it's akin to being stuck yelling out a window to communicate while everyone else is using the phone.
Overall, 90 percent of Americans making between $50,000 and $74,999 are online, according to a study released by the Pew Research Center in April. For those making more than $75,000 annually, it's 97 percent.
Among Americans who make less than $30,000 a year, however, just 62 percent are online.
And, only 43 percent of people without high school diplomas use the Internet, compared with 94 percent of people with college degrees.
"The more people without access to the Internet get left behind, the greater the gap between the haves and have-nots becomes," said Greta Byrum, technology expert with the New America Foundation, a nonpartisan public policy institute in Washington. "It robs people of a voice."
Being connected to the Web is "part of being a fully functioning member of our society," said Curtis Skinner, a family expert with the National Center for Children and Poverty at Columbia University.
Most people can't apply for jobs without being online. And a growing number of services for the poor - including food stamps - may soon be available online only.
In Florida, for example, people seeking unemployment benefits must apply online. Some can't, and a large proportion of claims are being denied, Skinner said.
How people get on the net is changing, of course. Among smartphone owners, for example, those with lower household income levels are more likely than other groups to say their phone is their main source of Internet access, according to Pew. Experts suspect that may be because smartphone Internet access can be cheaper and more convenient than owning a home computer with broadband access - an always-on, high-speed computer line.
A large percentage of poor Americans also get online by using computers in libraries.
In Philadelphia, the poorest city with more than one million residents in the United States, it is estimated that 41 percent of people lack access to computers in their homes, according to an analysis based on 2008 census material. Some researchers using updated figures, such as Temple University urban studies professor Charles Kaylor, believe the real number is closer to 54 percent.
David L. Cohen, executive vice president of Comcast Corp., which has created a program to get more low-income Americans online, said no more than 15 percent to 20 percent of residents were hooked up to broadband in poor communities.
By comparison, 85 percent to 90 percent of residents in better-off communities get broadband, Cohen said.
Overall, the Philadelphia metropolitan area (including Camden and Wilmington) ranks 35th out of 100 in broadband adoption rates, according to the most recent information compiled by the American University School of Communication. The Bridgeport, Conn., metropolitan area had the highest rate, at 77 percent of households. The Philadelphia metropolitan area registered 64 percent.
Interestingly, Skinner said, low-income students with Web access spend more time than their better-off counterparts using online time for games and social networking rather than schoolwork. That may be because there aren't that many low-income adults with sufficient computing acumen to police their kids, experts said.
To help poor people get online in Philadelphia, the Freedom Rings partnership - including city agencies, nonprofits, and Drexel University - has used federal grant money to create 77 KEYSPOT computer-access labs.
It's not easy for low-income adults to be cyber-savvy.
"This new world is strange for them," said Hamidou Traore, an instructor at the People's Emergency Center. "Their reading levels and writing skills aren't all there. It's overwhelming."
To help address such problems, Comcast last year created Internet Essentials, which offers a discounted $9.95-a-month home broadband Internet service to people whose children qualify for free or reduced-price school lunch. The program also helps low-income people buy a computer for $150.
The nation's largest provider of residential Internet service, Comcast agreed to the program as a condition of its deal to buy NBC Universal Inc., Byrum said.
"The whole company has a passion for this," Cohen said.
The program has had mixed results, with just 463 broadband activations in Philadelphia, as opposed to more than 5,000 in Chicago, Comcast figures show. Overall, 41,000 U.S. households signed up for it. "That's not much at all," Byrum said. The program doesn't allow the elderly or any low-income people without school-age children to participate, she added.
Philadelphia groups that represent the poor, notably Action United, say Comcast did a poor job of publicizing the program and set up too many hurdles to apply.
"We did a terrific job publicizing it," Cohen countered. In Philadelphia, for example, fliers were sent home with public school students. He added that senior citizens were not a target audience for Internet Essentials, and that applications were now easier.
Even if the Comcast program improves, it won't connect the poor to the Web overnight.
Besides, said Melissa Gilbert, urban studies professor at Temple, the poor suffer problems beyond the Web.
She related the story of a woman who showed up at a computer-training class with her brother. To see the screen, the two needed glasses. They were so destitute, however, they had to share a single pair.
"Are you concerned about access to the 'net if you're hungry?" Gilbert asked. "Probably not."
Contact Alfred Lubrano at 215-854-4969 or firstname.lastname@example.org.