For Harold Spilker, past job searches have always been more about quantity than quality when sending out cover letters. These days, however, the second-year MBA student is more deliberate: Seeking a job in finance, he has only sent out three cover letters and resumes in the past three months.

“It’s definitely about less volume and more targeted at this point in the game,” says Spillker, a student at the University of Maryland’s Robert H. Smith School of Business. “I spend all my effort on one or two and make sure I’m really interested in the company before I waste my time or their time.”

It’s a smart strategy in today’s job market, says Rob Parker, a managing director at recruiting and staffing firm Spherion, because of the extra care needed to distinguish yourself as a candidate when employers are awash in applications. “Cover letters are much more important than they used to be because of the tight labor market,” he says.

The cover letter can be a powerful document. A single sheet of paper, it can determine whether an employer will invite you to an interview in just three or four paragraphs.

A Sales Pitch -- And Much More

Why are cover letters so important? Your prose can determine whether a hiring manager will turn the page to view your resume and confirm that your background and skills match his needs; it can also serve as a de facto writing sample and glimpse at your ability to put sentences together without spelling or grammatical mistakes.

Apart from precision, recruiters and employers agree that the secret to effective cover letters is personalization. Successful job seekers, they say, use cover letters to illustrate what they know about the company they’re applying to and how their skills fit into the position being offered.

Gone are the days of printing off one letter and changing the recipient’s name. Instead, strong letters can help candidates connect with an employer before they ever set foot in the building.

A good cover letter -- all told, it should be no more than half of one page -- should open with an explanation of why the person is writing and what position they’re seeking. This is also the time to mention contacts within the company or the person who referred the candidate to the position. One way to open:

I’m writing in response to your company’s ad for a sales manager in the Washington Post on December 2, 2006. I’m also writing at the suggestion of Bob Jones, who recommended that I apply for the position.

The second paragraph should sell the candidate’s skills while explaining what the candidate knows about the employer, the position and how their skills fit the employer’s needs.

This means discussing both how a worker can help the company, explains Margie Decker, regional career development officer with Strayer University, rather than how a job is good for a job seeker’s career.

“The biggest mistake I see is [candidates] don’t think about how they relate to the organization,” Decker says. “It’s about the individual organization and not ‘me, me, me.’”

Some successful candidates use bullets to list their skills. Others have highlighted specific projects or experiences they’ve had that relate to the company’s position.

“If somebody gives me the right message in the cover letter, even if the resume is not perfect, I’ll call them,” says Parker. “The cover letter shows how well they would interview and present themselves ‘face-to-face.’” An example:

I have watched your company grow since its launch in 2000 and have read several articles about the new software you released last year. As you can see from my resume, I have five years of experience working in sales at ABC Software, where I spearheaded a marketing campaign for a new software package released in 2005. Under my direction, my team was able to generate $1 million in sales within the first year of the product’s release.

Vienna’s Billy Peterson, currently seeking a job in business operations or finance, sometimes uses the second paragraph of his cover letters to highlight his MBA and his status as a certified management accountant. He’s also brought attention to the fact that he’s looking to relocate near a company to be closer to his adult children. “I note that I’m considering them for family reasons,” says.

Can You Go Too Far?

Too much personalization, however, can be a mistake. As tempting as it may be to add personality to a cover letter, employers and recruiters say the tone of the letter should be serious.

“If it’s too cutesy, [the applicant] might not be serious,” says Tom Aichson, chief executive officer of Herndon, Va.-based National Corporate Housing, a growing temporary corporate housing firm. “We have a lot of fun people here, but that first impression ought to be, ‘Here’s who I am and this is what I can bring to the table.’”

Font and paper also matter with hard-copy resumes. Experts say Arial and Times New Roman are the fonts to use, along with paper that isn’t too heavy or too thin. “The fancy thick paper might get attention,” says Paul Villella, chief executive officer of Washington-area recruiting firm HireStrategy, “but it also causes you to ask, ‘Why did they bother?’ Your expectations rise so high.”

Hiring experts say it’s appropriate to end a cover letter with a message along the lines of “I look forward to hearing you” or, alternatively, a mention of a candidate’s intent to follow up with the employer in a few days. “That shows a more aggressive interest in the opportunity than laying back and waiting for a phone call,” Parker said.

Whichever is chosen, however, they agree that the latter strategy only works if the candidate intends to follow through. The follow-up, which can be done with a phone call or by e-mail, can be used not only to confirm receipt of the resume and cover letter but also to discuss the candidate’s skills further, ask questions about the hiring process or address questions.