While some 8,200 Mainers work in call centers or related operations around the state, some of their bosses insist blocking telemarketers from calling individuals on a national do-not-call list – which begins today – means less than meets the ear.

That’s because Maine’s call centers tend to be focused on incoming calls.

Even so, telemarketing is a fact of life for thousands of businesses, some of them in your back yard.

Bill Appel manages a call center in Hampden that employs 28 part-time telemarketers, for example.

While you might imagine the caller sitting in a cubicle inside a large, windowless building in a business park somewhere, the people who work for Appel make their calls from a log home just off Interstate 95.

Appel works for Sunrise Glass, an Ellsworth-based business that specializes in windshield replacement. His telemarketers call residents within the company’s service area, asking if they have a windshield that needs to be replaced.

For a small business like Sunrise Glass, the investment in office space, equipment, phone bills and staff for the marketing effort may seem large. But Appel said it is remarkably effective because, unlike many other sales calls people receive, the Sunrise Glass pitch is tightly targeted: You either need a new windshield, or you don’t.

“We’re not adding the 10th credit card to your wallet,” he said.

Appel believes most Mainers won’t register on the do-not-call list. Mainers suffer far fewer telemarketing calls than most states, he said.

“I believe Connecticut is the most heavily called state in the U.S.,” he said.

Still, Appel planned to study the impact the registry will have on his operation.

“I’m going to crunch the numbers tonight,” he said.

The state Department of Labor admits it does not have a firm grasp on the part played by call centers in the state’s economy.

In fact, said Glenn Mills, senior economic analyst for the department, the term “call center” has not been clearly defined. In the third quarter of last year, Mills determined call centers provided about 8,200 jobs in the state, out of about 591,000 jobs.

The national do-not-call registry targets those who make unsolicited “cold” calls to people in their homes, trying to sell everything from long-distance telephone and financial management services to vinyl siding and driveway sealer.

Mills said the state is unable to quantify the number of telemarketers in Maine who make the unsolicited calls, and so the true impact of the ban on those 8,200 jobs in unclear.

MBNA America, a credit card lender which operates in the United States, Canada, Ireland, England and Spain, tops the list of call centers for people like Mills.

MBNA employs about 4,200 in 10 Maine towns and cities. Almost everyone who works for the company dons a headset and talks on the phone, but most are not making “cold” calls to pitch the credit card.

Instead, most employees handle incoming calls from customers about bills, credit limits, address changes and the like. Others call customers who are behind on payments. Still others accept calls made by customers who are activating a new card.

“We’re not going to comment on the do-not-call bill,” MBNA spokeswoman Carolyn Marsh said Tuesday. In recent statements on the issue, MBNA officials have said the company supports the concept of the list because it will increase efficiency.

In the past, MBNA has said its centers in Portland, Brunswick and Orono, where part-time employment is offered, do make solicitation calls. Still, Marsh said, implementation of a do-not-call list would not change the way MBNA operates in Maine.

“It’s not going to affect our call centers,” she said. “We do all of our business on the phone,” she added, suggesting that if one activity is curtailed, other telephone work is still needed.

MBNA is advertising employment openings in Rockland, Camden and Belfast.

L.L. Bean is another Maine company for which the telephone is central. Spokesman Rich Donaldson said Tuesday that L.L. Bean does not make outbound calls other than to respond to customer questions.

The company supports the do-not-call list.

“We view it as a good thing for consumer rights,” he said.

L.L. Bean employs 3,800 year-round, and almost 20 percent of those work on the phone, Donaldson said. The company gears up around Christmas, adding 5,000 more employees. At that time of the year, 30 percent of staff work on the phone.

Taction, a Waldoboro firm formerly known as New England 800, was the first “call center for hire” in Maine, said founder Steve White. The business was launched in 1983, and employees answer customer calls for businesses such as Down East Enterprises’ book division, Samsonite luggage, McGraw-Hill Children’s Publishing, and Harbor Sweets of Salem, Mass.

After years of expanding for the last quarter of the year, White said, Taction now steadily employs about 150. Since the company does not make solicitation calls, the do-not-call list will have no effect on it.

“I signed up quick,” White said of the list. “And I signed my mom up in Virginia.”

Facts about call centers

What are they?

The industry defines a call center as a place where telephone calls either are placed or received in high volume.

How many are there?

About 140,000 in Canada and the United States.

How many people in Maine work in call centers?

One state labor expert estimates about 8,200. Numbers are hard to acquire because the state does not formally define “call center” as a type of employment.

What is a service bureau?

A call center for hire. Companies run networks of interlinked centers that can, among other things, handle a sudden surge in call volume.

How did call centers begin?

Generally, the lodging, banking and catalog industries are believed to have pioneered them, starting in the 1970s.