(REUTERS/Tyrone Siu)

For the most part, America's Internet-usage trends can be summed up in a few phrases. The Internet is now so common as to be a commodity; the rich have better Internet than the poor; more whites have Internet than do people of color; and, compared with low-income minorities, affluent whites are more likely to have fixed, wired Internet connections to their homes.

But it may be time to put an asterisk on that last point, according to new data on a sample of 53,000 Americans. In fact, Americans as a whole are becoming less likely to have residential broadband, the figures show: They're abandoning their wired Internet for a mobile-data-only diet — and if the trend continues, it could reflect a huge shift in the way we experience the Web.

The study, which was conducted for the Commerce Department by the U.S. Census Bureau, partly reaffirms what we already knew. Low-income Americans are still one of the biggest demographics to rely solely on their phones to go online. Today, nearly one-third of households earning less than $25,000 a year exclusively use mobile Internet to browse the Web. That's up from 16 percent of households falling in that category in 2013.

(NTIA)
(NTIA)

And they're often cited as evidence of a major digital divide; struggling families with little money to afford a home Internet subscription must resort to free public WiFi at libraries and even McDonald's to do homework, look for jobs and find information.

But as the chart above shows, even people with higher incomes are ditching their wired Internet access at similar or even faster rates compared with people who don't earn as much. In 2013, 8 percent of households making $50,000 to $75,000 a year were mobile-only. Fast-forward a couple of years, and that figure now stands at 18 percent. Seventeen percent of households making $75,000 to $100,000 are mobile-only now, compared with 8 percent two years ago. And 15 percent of households earning more than $100,000 are mobile-only, vs. 6 percent in 2013.

Stepping back a bit, as many as 1 in 5 U.S. households are now mobile-only, compared with 1 in 10 in 2013. That's a doubling in just two years.

This suggests that having only one form of Internet access instead of two may no longer be explained simply as the result of financial hardship — as might be the case for lower-income Americans — but could be the product of a conscious choice, at least for wealthier people, who are deciding that having both is unnecessary.

These results paint the clearest picture yet of a country moving away from fixed networks toward wireless networks. They highlight how, for many, 4G LTE and other wireless technologies could be turning into viable substitutes for home broadband. And it helps explain many of the changes consumers are seeing in the marketplace.

Verizon, AT&T and other cell phone companies always compete for spectrum. But what is it, and how is it affecting your cell phone service? (Jhaan Elker/The Washington Post)

Companies such as Verizon are increasingly shifting to prioritize mobile service over wired service. Cable companies are exploring how to compete with telecom companies for wireless customers by setting up cheap, public WiFi hotspots that allow for voice calls and Web browsing. Google and Facebook, too, have experimented with the idea of beaming Internet wirelessly down to devices on the ground.

All this is happening because companies perceive a tremendous opportunity to make money in mobile Internet. And considering how even the wealthy appear to be voting with their feet, it appears the industry may be onto something.

Update: The study is now available on the government's website.