Are we killing off the cover letter?

June 8, 2012, 2:30 PM UTC

FORTUNE — In theory, the cover letter is a great idea. It’s intended to be a direct line of communication to the people who make hiring decisions. And if it’s actually read, it can build rapport with recruiters, set you apart from other candidates, and add context to your application. But that’s a big “if.”

Increasingly, employers aren’t even giving a first glance to cover letters that applicants submit. In 2009, Phil Rosenberg, president of reCareered, an online hub for job search advice, surveyed over 2,000 hiring managers, HR reps, and recruiters working in different industries and found that, more often than not, cover letters don’t come into play. “I found 90% ignored them and 97% made a decision whether to interview or not based only on the resume.”

So who or what is at fault for the demise of the cover letter? Any why are so many employers requiring it if they don’t even read them? It comes down to a combination of changes in technology, human behavior, and the job market in general.

How we got here

In the 1990s, employers and recruiting firms started building relationships with early job boards, such as Monster and Careerbuilder. At this time, the job boards and the applicant tracking systems (ATS) that companies and recruiting firms use internally were integrated and the level of automation and default options were set up. This job was primarily handled by IT departments, not recruiters or HR, says Rosenberg, who was a manager at staffing firm Robert Half in the mid-2000s. “There were default options. And one of those default options was to ask for cover letters. So every ad my company ran asked for cover letters but, strangely, my recruiters didn’t get them.”

MORE: When your office is like a reality TV show

Rosenberg noticed that his colleagues in the recruiting field were experiencing this too. He found the problem was that in most cases the ATS and other internal HR systems weren’t set up to keyword search cover letters. So recruiters would never see the cover letters as they typed in a few keywords when looking for solid candidates.

Recruiters weren’t shedding any tears over the loss. A lot of recruiters don’t have time to dig into the cover letter anyhow. “Whether it’s a recruiter or an HR department, the job is to efficiently find people that meet minimum qualifications,” says Rosenberg. “It’s not to find people with best qualifications. And these are processes that have been almost universally adopted, even with small firms.”

Add to that the fact that in a stagnant job market there are an overwhelming number of candidates for every open position. “You gotta remember we used to be in a job market that was pretty consistently, from WWII to 2007, a job market of candidate shortages and skill shortages,” says Rosenberg.

Inevitably, as companies grow, they’re less likely to put as much individual attention into their recruiting, says Don Charlton, founder and CEO of The Resumator, an online hiring software firm. “The larger the company, the more it becomes automated and robotic. That’s why large companies have so many mediocre people. That’s why a company’s heyday is when they’re hiring the best 75 people they can find.”

Is it curtains for the cover letter?

Things have gotten so bad for the cover letter that Rosenberg has started advising clients to put their effort into customizing their resumes and forget the cover letter entirely. “The process is set up to reward candidates that heavily customize their resumes for each individual opportunity, company, and hiring manager,” he says.

While you can’t blame candidates for playing into the system, are we really prepared to abandon the resume’s longtime companion altogether? We’ll always need a tool to introduce ourselves and sell folks on our best qualities. We’ve been doing it for centuries. Even Leonardo da Vinci used a cover letter of sorts to pitch his services to the Duke of Milan. Although this has been called the first resume, it’s really more of a cover letter, or what probably would have been referred to as a letter of introduction. It’s likely that the curriculum vitae (CV) and resume evolved from the cover letter as a more nuts and bolts presentation of a candidate’s skills and accomplishments.

MORE: A closer look at the labor market’s ‘new normal’

It’s hard to say when the cover letter and resume emerged as separate entities, says Sean Weinberg, co-founder of RezScore, an online resume analyzer, but he places it somewhere in the early twentieth century. “It’s been a slow evolution. The cover letter as we know it has evolved in parallel with the resume.” (His company published a nifty infographic on the history of the resume.).

When a letter just doesn’t cut it 

Job openings that don’t require a high level of verbal and written skills place less emphasis on the cover letter. As COO of Knewton, an online learning company, David Liu oversees the company’s recruiting strategy, and he does not put much stock in the cover letter. “We’re hiring engineers to business people 20-to-one right now. When we’re looking for people in the areas of software development and engineering, we’re not really looking to see how well you write prose. We’re looking to see how well you code and how well you can design a system.”

Liu says they get to know candidates by looking at their portfolios, through coding tests, and in conversations so that they can understand what they’ve actually accomplished. “With cover letters, you can’t really get into a lot of detail without it getting blown into an eight-page document.”

Liu argues that a resume with a referral or approaching employers through another context would work better than any cover letter. “Just sending in a blind cover letter is absolutely dated,” he says. “You need to figure out a way to identify with the folks that are in those companies. There are meetups. There are ways to find out who’s working there, for how long, and what they do.”

MORE: Recent college grads: They’re not so bad at work

But not everyone is ready to call it quits on the cover letter. “The cover letter is the only thing you have that separates the person from being a candidate and being a human being,” says Charlton. “Resumes are about skills, cover letters are an opportunity for a person to indicate their desire to work for a company.”

In other cases, the cover letter can help answer questions about the candidate that may have been raised by the resume, says Brian Bruce, vice president, Premier Solutions Restaurant Recruiting. “Sometimes there’s some explanation needed. If they’re sending me a resume and all their experience is in California, in the cover letter portion they can say, ‘I’m moving to Pennsylvania in six weeks.’”

Charlton sees the marginalization of the cover letter as an “erosion of professionalism” and if nobody is looking at these cover letters, that’s a problem with recruiting. “A good cover letter followed by a good resume, that’s like brains and beauty.