The Obama administration has made a major push to expand broadband access to the poorest and most rural parts of the country, and they have largely succeeded. A recent Federal Communications Commission report noted that nearly all U.S. households were in an area with at least one high-speed broadband provider.

But whether people can afford broadband is a different story.

States in the Deep South have among the lowest rates in the country of households connected to broadband, according to the most recent data from the U.S. Census Bureau's American Community Survey.

Just 57.4 percent of Mississippi residents live in households with broadband Internet use. Many other Southern states rounded out the top 10 least connected, with Arkansas at the second to last, and other states, including Alabama, Kentucky and Louisiana, also reporting low levels of home broadband use.

The reason is pretty obvious once you compare the above map to one that shows median household income.

Mississippi, the state with the lowest rate of broadband use, also has the lowest median household income in the country: just below $38,000. Other Southern states with low connectivity rates ranked near the bottom when it came to incomes, too. States with higher incomes in the Northeast and on the West Coast report higher median household incomes -- and higher levels of home broadband use.

This suggests that the biggest barrier to someone having access to the online world is cost. More than half of Americans in households making less than $25,000 per year live in a home without an Internet subscription, compared to about 5 percent of those living in households making more than $150,000 per year.

"Cost is a huge factor in terms of broadband adoption, and in the U.S. we tend to pay more for broadband at entry level speed tiers as well as the higher levels," said Danielle Kehl, a policy analyst at the New America Foundation's Open Technology Institute.

Americans pay more for comparable broadband plans than the rest of the world, including their peers in Asian and Europe, a recent report from the organization found.

One reason for this, Kehl suggests, is that there isn't enough competition to drive down the cost of broadband subscriptions. As you can see in this chart from the FCC below, more than a third of Americans live in areas served by two or fewer fixed-location Internet providers with download speeds of at least 6 megabits per second -- enough for basic Internet use but not ideal for streaming video.

In theory, more competition in the broadband marketplace should drive down the costs of subscriptions. As it stands now, though, more than a third of Americans live in areas served by two or fewer fixed-location Internet providers with download speeds of at least 10 megabits per second, according to the FCC. It takes a lot of providers, about five or six, competing in a location for consumers to see a substantial price difference, Kehl said.

These issues of cost and competition are before the FCC now as it reviews the $45 billion merger between Comcast and Time Warner Cable. The companies have argued that their customers don't overlap in enough parts of the country for the deal to be a problem, but consumer advocates still worry that bigger ISPs equal bigger costs for consumers.