(FORTUNE Small Business) – If you're building a Yahoo wannabe, getting wired is a no-brainer. But if you're a not-com that's doing just fine without fancy computers and an ultrafast Internet connection, investing in technology probably sounds as absurd as money-hemorrhaging dot-coms valued in the billions. Well, the dot-coms may not be worth what they used to be, but a new slew of them are targeting traditional small businesses that have thrived offline for years and seem immune to the benefits of technology.

Known as vertical service providers, these dot-coms generally offer a package consisting of a computer, Internet access, and applications tailored to a company's industry--all starting around $100 per month. The concept has gained the most momentum in the restaurant, nightclub, day-care, and car-repair businesses, but fledgling offerings are available for golf courses, spas, and real estate agents. This leads us to believe there'll soon be similar deals in many other industries, so the time is now to decide whether these services make sense and what to look for in one.

The promise, of course, is that the technology will revolutionize the businesses that sign up, bringing in new customers and revenue while saving time and money. But do you really need the apps being offered, and will they adapt and grow as your company does? The decision you make could be the difference between being a prescient early adopter and getting stuck with a useless heap.

Whether a service will work often comes down to the appeal of the application to consumers. Nowhere is this more evident than in the day-care industry, where companies like New York City-based ParentWatch are installing Web-based surveillance systems that let parents log on from work and see their children playing and napping. Robin Siekerman of Douglasville, Ga., whose two-year-old son, J.T., goes to Kids R Kids, a ParentWatch customer, says, "If we had to change day-care centers, it would be very hard for me to go to one that didn't have the service." She's happy to pay the $24 a month that ParentWatch charges parents to access the system because "it's peace of mind."

The service providers also need to drive new customers to member businesses through the Web.OpenTable.com, a San Francisco service whose tools help its 800 restaurants in major U.S. cities coordinate online reservations and collect customer data, lures diners to its site through deals with the city guide digitalcity.com and the online version of the popular Zagat restaurant surveys.

George Knowles, assistant director of food and beverage at the Campton Place Restaurant in San Francisco, says he gets 25 online reservations a week through OpenTable. It's a fraction of the 400 weekly reservations he logs, but Knowles says the tabs more than pay OpenTable's fees. "Each of those 25 people is bringing in an average of three to four people, and the average bill is $100 per person," he says. So Campton Place can recoup its OpenTable expenses, about $400 a month, with just one table for four on a Thursday night.

If the tools are used well, participating businesses will be able to enhance the customer experience in ways not easily done offline. Bill Grefe owns Ark Automotive in San Marcos, Calif. He has found only one new customer in four months through MechanicNet, a Fremont, Calif., company that gives auto repair shops customized Websites and e-mail, but that customer will be one for life. Grefe's staff impressed its new client by greeting her by name when she arrived at the shop for the appointment she had scheduled online and by preordering the part she needed before she came in.

Not every application focuses on the customer; some help businesses run their operations better. In the nightclub and bar industry, video surveillance is the app of choice for service providers to help owners keep theft and employee laziness in check. New York City restaurant and bar owner John Heil hired cEverything, a San Francisco company, to install videocameras linked to the Web. Heil says closed-circuit surveillance would have cost $10,000 just to install--compared with the $100 a month he pays cEverything--and with closed-circuit cameras he wouldn't be able to keep an eye on workers from home. He has saved thousands of dollars in lost inventory (workers behave better when they know they're being watched, he says) and has increased productivity by flagging managers when he spots idle employees.

Picking a service provider also means betting on whether it'll be able to meet your business needs as you grow. The evolution of the services is largely ad hoc. Gerry Klaskala, the owner of Aria Restaurant in Atlanta, asked OpenTable if the touch-screen reservation application could be integrated into his phone and point-of-sale systems. "It only makes sense," he says. OpenTable responded to Klaskala and soon will roll out a tie-in with point-of-sale systems.

This won't last forever, though. After all, these service providers aren't consulting firms, and the offer has to get more uniform. "We have a standard service," says Adam Aronson, CEO of the well-established ParentWatch, which has 2,000 day-care centers in its network. "If you're a center in Oklahoma, for instance, and want something very specific that's not on our platform, you're not going to get it."

The one-app-fits-all solution turns off some potential customers. Unwired restaurant owners say that computerized table booking, which ostensibly maximizes a restaurant's capacity, is flawed if you have the flexibility to change the floor plan. "If all of your tables were nailed to the floor, the system wouldn't be a problem," says David Abes, owner of Insignia restaurant in Atlanta. Otherwise, "there's always room to squeeze in more people."

It does require a leap of faith for early adopters to buy into any system being offered to help get their businesses online, but those who have done it say it's worth a try. Campton Place's Knowles is convinced. "It's better to be up and running with it now, rather than wait until you're losing business because you don't have it."