In this crowded job market, it's getting harder to stand out from the crowd.

That's why job hunters increasingly tap professional marketers to improve their prospects. Experts such as executive-marketing firms, executive agents and certified personal-branding strategists claim to provide more tailor-made guidance than conventional coaches.

Business is booming. About 100 Wall Street executives requested assistance during 2008 from David Werner International Corp., a New York executive-marketing firm that serves just four individuals a month. Neal Lenarsky, a Los Angeles executive agent, receives three times more calls from potential clients than several months ago. Paul Copcutt, a branding strategist in Dundas, Ontario, reports a similar recent pickup in demand.

But you could spend plenty for such services with scant results. In the past, state agencies cracked down on numerous career-marketing concerns for charging hefty upfront fees without fulfilling their promises. "A lot of people would like to make money off job seekers," cautions Joseph Daniel McCool, a management-succession consultant in Amherst, N.H. "Not all will bring you the ideal job at the end of the rainbow."

Here's a guide so you can weigh the pluses and minuses before buying "expert" advice about peddling the brand called You Inc.:

Executive-marketing firms

David Werner International aids executives earning at least $300,000 annually. The firm revamps each client's résumé and sends letters touting his or her qualifications to as many as 3,000 companies, says David Werner, its president. Because most prospects are employed, the letters usually omit their identities. Clients typically pay $26,000 plus a $13,000 "success fee" if they land positions through the company.

Craig Schmeizer, a senior credit-card executive for Washington Mutual Inc., became a Werner client shortly before he left WaMu last spring. Mr. Werner initially dispatched about 315 letters to officials and board members at 114 insurance and financial-services companies, according to Mr. Schmeizer. As a result, the executive says he interviewed for attractive spots at five corporate giants, remains in the running at one and obtained a temporary consulting gig with a $200 million Internet concern.

Mr. Schmeizer believes the $30,000 he has given Mr. Werner was money well spent — despite his lack of permanent employment. "I'm happy to pay David a bigger success fee if his work helps me take on an even more meaningful assignment than the last."

Certain Werner clients are unhappy, however. Steven L'Heureux, a California broadcast-technology executive, says Mr. Werner contacted 962 concerns on his behalf without naming him. The letters "didn't produce a single interview," the executive recalls. "A blind mailing campaign is not the best way to get a job."

Mr. Werner disagrees. He says Mr. L'Heureux's name was disclosed in certain letters and the former client "did get interviews" because he paid $5,500 after obtaining at least one interview. Mr. L'Heureux says he used Mr. Werner because "he promised his approach would generate results." He says he paid Mr. Werner a total of $22,000, but didn't pay the $11,000 success fee due if he had gotten a job through Mr. Werner's efforts. On his own, the executive got a new job last month as chief operating officer of a California technology concern.

Executive agents

Executive agents are personal talent scouts, similar to their sports counterparts. They arrange introductions at selected employers, coach during offer negotiations — and continue counseling clients once they find jobs.

In exchange, agents charge plenty. Mr. Lenarsky usually collects a $25,000 retainer plus 6% of a client's total annual compensation if the agent continues to counsel the client after a hire. Matt Pillar, co-founder of an investment firm in Santa Monica, Calif., says the agent opened doors for him in summer 2007 by calling officials at a major entertainment and media company where Mr. Lenarsky once worked.

Mr. Pillar landed a vice presidency there weeks later. He retained the agent for on-the-job coaching until he quit last fall. Job hunting again, Mr. Pillar gleans leads from Mr. Lenarsky. He represents "another tool in my toolbox," Mr. Pillar explains.

The downside? Only a handful of executive agents operate in the U.S. "It's really hard to make a living out of this," says Joe Meissner, a Portland, Ore., agent since 1993. He now solely represents "bankable" chief executives interested in buying a business.

Certified personal branding strategists

Branding specialists are more plentiful — and cheaper. Nearly 300 people, mainly career coaches, have completed a 12-week certification program run by Reach, a New York personal-branding company. They charge clients between $2,000 and $20,000, according to William Arruda, Reach's founder.

Strategists help job seekers recognize their unique strengths, determine their target audience, craft a "personal brand statement" and improve their online identities. The approach paid off for a London, Ontario, client of Mr. Copcutt's, Julie Chen, who practices naturopathic medicine, which uses natural remedies such as herbs.

In February 2008, Ms. Chen persuaded a Canadian maker and distributor of nutritional products to pick her as its new product-development manager despite her limited experience. She touted her related skills and attributes. Without personal brand coaching, she says, "I would have had a very tough time getting this job."

But the branding process can take months, discouraging applicants eager to find employment fast. To reduce anxiety among layoff victims, Reach recently launched a free "Career Bailout" program — in which 13 certified strategists provide services such as a résumé review and online identity evaluation. Yet few victims are using the limited assistance. "We have not spent enough time making the program visible," Mr. Arruda says.