Mobile data cards that connect computers online through a wireless carrier's network are becoming a popular method of home Internet access.

A new report from market researcher Nielsen Mobile claims that there were more than 13 million wireless data card users nationwide in the second quarter of this year. An estimated 55 percent of these cards were bought in the past 12 months, indicating rapid adoption.

"Wireless carriers are in the relationship business, so it should come as no surprise to us that they find more and more ways to entrench themselves in the consumer experience," said Nic Covey, Chicago-based director of insights at Nielsen Mobile.

"The more complicated the relationship, the more difficult to get out," he said. "Consumers should be the beneficiaries of the increasing competition for share of connection."

Wireless data cards from carriers such as Sprint, AT&T and Verizon Wireless are regularly advertised in print, online and on television as part of their mobile broadband network.

These cards are available in different formats.

ExpressCard and PCMCIA cards that slide into slots on the desktop or notebook computer account for 54 percent of the market, followed by USB cards' 30 percent share. Embedded cards that are built into computers hold a 17 percent share of wireless data cards.

The nearly 1,300 mobile data card users that Nielsen Mobile surveyed reported spending an average $65 on their data card, excluding service costs.

"Consumers have become accustomed to the ubiquity of information," Mr. Covey said. "As consumers, we want enabling technology that is simple and reliable.

"Today, wireless data cards provide consumers with a straightforward and dependable means of around-the-clock, on-the-go access to information," he said.

"Increasingly, consumers view a disconnected computer as a dead computer. Wireless data cards breathe life into an otherwise lame information-less piece of metal and plastic, reuniting consumers with the world."

Cards hit home
Mobile data cards are popular with business travelers. But it is their inroad into the home and personal Internet access markets that is worth watching.

Forty-three percent of the mobile data card users surveyed by Nielsen Mobile said they most often use their data card at home, with another 15 percent reporting its use at work.

Also, 21 percent of those surveyed and responding said they used the card outdoors and 9 percent while commuting.

Almost all of the respondents had other means of Internet service at home. Two out of five card users had cable broadband and 34 percent had DSL at home.

However, 59 percent of the responding card users said they might swap their Internet service provider for exclusive data card usage, indicating shaky loyalty and low switching costs for ISPs.

How soon that threat to ISPs will materialize is a matter of question.

"For many consumers, the speeds offered by data cards won't just be fast enough to threaten their ISP business," Mr. Covey said.

"But for the casual Internet user, particularly single users living alone, the choice between $60 for tethered home Internet access or $60 for Internet that they can take with them is becoming an interesting one," he said.

ISPs should monitor data-card penetration closely and consider how their products and messaging remain competitive, the Nielsen Mobile analyst said.

Faster speeds and easier home wireless network capability will help ISPs remain more competitive. Exploring partnerships with public Wi-Fi networks to allow online portability for home customers will also help retain current business.

ISPs can also argue that mobile data cards cannot handle the flow of media-rich files that faster dedicated home access lines would. But that may be a problem chasing a solution -- at least, as of now.

"Today, data cards aren't ideal for media-rich Internet experiences, but most consumers aren't streaming a movie every time they sit down at the PC, either," Mr. Covey said.

"For most of what consumers are doing on the Internet, wireless data cards are today more than sufficient," he said. "As network speeds and pricing models evolve, they will allow for even more robust data card access."

Expand contract
Consumers sign up for mobile data cards with a contract that is similar to their mobile phone service. They also get a subsidized card if when they sign up for a two-year mobile phone contract.

All the major wireless carriers offer mobile data cards only on a contract basis.

But mobile wireless network operator Cricket is one of the few in the space to offer a month-to-month wireless data card service at http://www.mycricket.com/broadband. It is available only in select ZIP codes where Cricket has wireless coverage.

"Data card access without contracts could allow consumers to experiment with the service, but interest in contracted broadband access will far outweigh the month-to-month alternative," Mr. Covey said.

"Today, portable broadband is not a necessity," he said. "It's still somewhat of a luxury."

One hurdle to quicker market adoption is the wireless data card's pricing.

While the cards are cheap or free, in some cases, access rates need close attention, Mr. Covey suggested.

"Each of the leading carriers has a pricing-model-based data use, so heavy users could end up paying for it," Mr. Covey said. "That will change, though.

"Communication access trends toward unlimited pricing models," he said, "and I think mobile data card rates will as well. I suspect carriers are content to move this way once they're confident they have sufficient bandwidth."

Wired card entries
AT&T and Verizon Wireless, the nation's No. 1 and No. 2 carriers, respectively, are close competitors in the wireless data card market.

Both carriers entered the data card market at roughly the same time and have similar offerings. The advantages they hold over rivals such as Sprint, which advertises its services heavily, is the breadth of network coverage that translates into more marketing clout for their data cards.

The interplay between expanding phone and data card-based mobile broadband access will be interesting to watch in the next two years, Mr. Covey said.

"What's clear is that consumers will expect far more than voice access from their carrier, but are looking for this means of larger connectivity," Mr. Covey said.

"In the relationship business of the wireless world, the formula for success is rather simple: the most ubiquitous access, including voice and data, at the lowest cost," he said.

"The expanding data card market allows operators to take that competitive offering beyond the wireless world and further across the consumer connectivity market."