(Fortune) -- If you need a job, or just want a better one, here's a number that will give you hope: 50,000. That's how many people the giant consulting firm Accenture plans to hire this year. Yes, actual jobs, with pay. It's looking for telecom consultants, finance experts, software specialists, and many more. You could be one of them -- but will Accenture find you?
To pick these hires the old-fashioned way, the firm would rely on headhunters, employee referrals, and job boards. But the game has changed. To get the attention of John Campagnino, Accenture's head of global recruiting, you'd better be on the web.
To put a sharper point on it: If you don't have a profile on LinkedIn, you're nowhere. Partly motivated by the cheaper, faster recruiting he can do online, Campagnino plans to make as many as 40% of his hires in the next few years through social media. Says he: "This is the future of recruiting for our company."
Facebook is for fun. Tweets have a short shelf life. If you're serious about managing your career, the only social site that really matters is LinkedIn. In today's job market an invitation to "join my professional network" has become more obligatory -- and more useful -- than swapping business cards and churning out résumés.
More than 60 million members have logged on to create profiles, upload their employment histories, and build connections with people they know. Visitors to the site have jumped 31% from last year to 17.6 million in February. They include your customers. Your colleagues. Your competitors. Your boss. And being on LinkedIn puts you in the company of people with impressive credentials: The average member is a college-educated 43-year-old making $107,000. More than a quarter are senior executives. Every Fortune 500 company is represented. That's why recruiters rely on the site to find even the highest-caliber executives: Oracle (ORCL, Fortune 500) found CFO Jeff Epstein via LinkedIn in 2008.
The reason LinkedIn works so well for professional matchmaking is that most of its members already have jobs. A cadre of happily employed people use it to research clients before sales calls, ask their connections for advice, and read up on where former colleagues are landing gigs.
In this environment, job seekers can do their networking without looking as if they're shopping themselves around. This population is more valuable to recruiters as well. While online job boards like Monster.com focus on showcasing active job hunters, very often the most talented and sought-after recruits are those currently employed. Headhunters have a name for people like these: passive candidates. The $8 billion recruiting industry is built on the fact that they are hard to find. LinkedIn changes that. It's the equivalent of a little black book -- highly detailed and exposed for everyone to see.
For a generation of professionals trained to cloak their contacts at all costs, this transparency is counterintuitive. So far most conversations about how to use social networks professionally have focused on what not to do: Don't share drunken photos on Facebook. Don't use Twitter to brag about playing hooky from the office.
But as companies turn to the web to mine for prospective job candidates, it's no longer advantageous to refrain from broadcasting personal information. Instead, the new imperative is to present your professional skills as attractively as possible, packing your profile with keywords (marketing manager, global sourcing specialist) that will send your name to the top of recruiters' searches.
At the same time, you can connect your online professional interactions in one place, joining groups on the site (LinkedIn has more than 500,000 of them, based on companies, schools, and affinities), offering advice, and linking your Twitter account and blog updates to your profile.
"You Google other people, so don't you think they're Googling you?" LinkedIn founder Reid Hoffman asks. "Part of a networked world is that people will be looking you up, and when they do, you want to control what they find." Helping you present yourself well online is just the start. LinkedIn plans to go far beyond, making itself an active and indispensable tool for your career path. The secrets lie buried in the data: those 60 million profiles, including yours.
In a business where data wonks are rock stars, Dipchand ("Deep") Nishar is Bono. During his five-year tenure at Google (GOOG, Fortune 500), Nishar, 41, was instrumental in developing its ad platform, its mobile strategy, and products for the Asia-Pacific region. Hoffman spent almost a year recruiting him to be vice president of products, until finally, in January 2009, Nishar took a right out of Google's Mountain View, Calif., parking lot and drove two blocks to his new office at LinkedIn's headquarters.
Having so much experience in Asia, where mobile messaging and other social networks were adopted even faster than in the U.S., Nishar understood the value of a system that would help consumers organize all those digital relationships.
But it was one personal interaction that really sold him on LinkedIn's potential. Nishar was trying to decide whether his daughter, who was 12 at the time, should spend her summer at a program offered by Johns Hopkins University. He posted the question to his status update on both Facebook and LinkedIn. While he received more comments on Facebook, they were casual and congratulatory. Only four of his LinkedIn contacts wrote him, but they offered a rich analysis, describing experiences with the Johns Hopkins program that left them better off academically; they persuaded him to enroll his daughter. "People are in a different context and mindset when they're in a professional network," he says.
This was Hoffman's bet when he founded the site in 2003. It was just after eBay (EBAY, Fortune 500) paid $1.5 billion to buy PayPal, where Hoffman had been a founding board member and executive vice president, and he was casting about for his next big project. Hoffman, 42, was already one of Silicon Valley's most hyperconnected players, with investments in dozens of other startups (including Facebook), so it was natural for him to think of a way for people to build on their links.
"I realized that everyone will have their professional identity online so they can be discoverable for the things that will be important to them," he remembers, waving his hand as he sits back in his chair. "The obvious one is jobs, but it's not just jobs. It's also clients and services. It's people looking to trade tips on how you do, say, debt financing in the new capital markets." Backed by other angel investors like him, Hoffman and four others put up the initial funding and gathered a tiny staff to launch the site as a bare-bones operation in his Mountain View home.
At first, users were slow to embrace the service. Plenty of Web 2.0 entertainment websites were enjoying meteoric rises and monstrous buyouts by big media companies. (In fact, after helping fund YouTube, Hoffman gave its founders office space for three weeks in their early days.)
By comparison, LinkedIn seemed a little static; it was only for résumés. As Facebook caught on among bona fide adults, it created a population of web users fluent in updating their status, posting links, and microblogging. Hoffman could sense that social networking was finally becoming mainstream, and he needed to give LinkedIn's users a reason to stick around before they moved their résumés and other professional information to platforms like Facebook. So last December he recruited former Yahoo exec Jeff Weiner to step into the CEO position. And he won over Nishar.
John Klodnicki wasn't looking for a job when he took the call from an IBM recruiter who had found his profile on LinkedIn. As a program director for data-storage company EMC, he spent five days a week on the road consulting with pharmaceutical companies. "I was moderately happy," he said. Sure, all that traveling was a drag.
On that Friday afternoon Klodnicki was scarfing a sandwich while standing in the security line at the airport in Providence, trying to get home to his family in New Jersey. The line was long, so he had the time to chat about opportunities. After going through several rounds of interviews, the initial job fell through, but the relationship had been started. He kept in touch, and last September, Klodnicki started work as an associate partner developing new business with pharmaceutical companies at IBM's Philadelphia office, just half an hour from his home.
Thanks to LinkedIn, people like Klodnicki are increasingly easy to find. "It's a great equalizer for us. It gives the recruiter an opportunity to reach out directly to a candidate," says Annie Shanklin Jones, who heads U.S. recruiting for IBM (IBM, Fortune 500). "In a company the size of IBM, that's significant."
IBM has always been one of the first companies to experiment with new social technologies. Its recruiters use Twitter to broadcast job openings, and the company organizes its own talent communities. But Jones says LinkedIn is the most important social-media site for reaching prospective hires.
Cost saving is a major motivation for companies looking to bypass big headhunting firms. "If I were going to go out to a major recruiting firm, for example, we could potentially pay upwards of $100,000 to $150,000 for one person," says Accenture's Campagnino. "Start multiplying that by a number of senior executives, and you start talking about significant numbers of dollars very quickly."
If anybody should be nervous about that, it's L. Kevin Kelly. As CEO of Heidrick & Struggles, one of the most prominent recruiting firms, he has made a living out of the hiring market's opacity. As he watched the rise of LinkedIn, he knew it was a disruptive force he would have to learn well; last summer he flew to the Bay Area to have dinner with Hoffman.
Their companies have a complicated relationship. On the one hand, LinkedIn is a welcome tool for recruiters, and Heidrick & Struggles is a customer. LinkedIn's software allows recruiters to search its database without access to photographs, thus keeping in compliance with antidiscrimination laws, and to contact anybody in the LinkedIn network. But the recession forced companies to cut back on their budgets for outside firms.
Heidrick & Struggles' revenues fell 36% in 2009, and while business has started to creep back, Kelly is aggressively trying to remake the company as an adviser rather than simply a search company, offering consulting on ways to handle staffing issues and select board members. Now it's just 7% of the business, but he expects it to grow to half of what Heidrick & Struggles does.
There will still be a need for headhunters and traditional methods of hiring, though, because LinkedIn doesn't work for everything. And it has to be used carefully.
"If you're not managing that site, you can erode your brand," says Arlette Guthrie, the vice president of talent management at Home Depot. Guthrie has learned how to use the site through trial and error. Over the past few years she experimented with using LinkedIn for all hires -- including seasonal workers, Home Depot will need 80,000 people in the next year -- but discovered that LinkedIn didn't offer better applicants for the bulk of the company's positions, mostly in their retail stores. Though plenty of cashiers and doctors and teachers join LinkedIn, the site's primary membership is corporate professionals.
Now Guthrie uses LinkedIn mostly for three hard-to-fill areas: supply chain, information technology, and global sourcing. Some of Guthrie's recruiters spend time daily on the site, reading up on potential candidates, chatting with them in groups and on message boards, and responding to inquiries. The approach has worked well. Using services like this on the Internet she has been able to bring down the time it takes to fill the positions, an important metric among recruiters, by nearly half.
At the entry to the "Hope" classroom on the satellite campus of Belhaven University in Houston, Susan Thorpe passes out a small book called 12.5 Ways to Get Ahead on LinkedIn. Up front, her husband, Doug Thorpe, who self-published the guide, has drawn a diagram on the whiteboard that looks like an elaborate football play. A series of circles labeled one, two, and three stretch out from a central bubble labeled you. A dozen job seekers take notes as Thorpe describes how to call upon first-level contacts -- those former colleagues and friends you've befriended on the site -- to reach second-level contacts. It's a process as old as human relations: Hey, could you introduce me to your friend? Thorpe explains the etiquette and technique of doing it digitally. "Write a personal note when you ask someone to connect," he tells his students.
Thorpe, 57, is one of hundreds of consultants who have sprung up to help professionals establish themselves online. After he lost his mortgage company two years ago in the real estate crash, he started Jobs Ministry Southwest, a religious nonprofit that offers free support for job seekers in the greater Houston area. A dozen of the 160 people who attended the previous day's support group have paid $24.95 for a half-day introduction to LinkedIn.
Thorpe's main message to his clients is that it's important to complete your profile. Get recommendations from former co-workers. Use keywords to bring out the skills you want to highlight. Join groups: Recruiters often scour professional groups to round up potential candidates. Answer questions from colleagues that showcase your professional expertise.
One of the students, Heinz Meyer, exhales audibly at the prospect of all that time online. "This could turn into a 24/7 thing real quick," says Meyer, 67, who had just lost his job at Universal Pegasus, a pipeline construction company. Thorpe responds by suggesting the class spend a concentrated amount of time on the site each day, say 30 minutes. Believe it or not, LinkedIn doesn't pay this guy.
There is much debate in the class about Thorpe's suggestion that job seekers should include professional photographs with their profiles. ("Don't use dogs, horses, cats, or cows in the background," he says.) Older job seekers in particular are worried that their gray hair will trigger age discrimination. There are drawbacks to so much transparency, they argue. Doesn't it ensure that employers potentially know more about you than they should?
It's a question Hoffman considered right from the start. For all the benefit that LinkedIn brings to the job hunt, it can't erase fundamental challenges in the job market. One big reality is that plenty of baby boomers are out of work as the industries in which they've developed three decades of expertise move overseas or change irrevocably.
These job hunters will need to reinvent themselves in new careers. The thing about social-networking profiles is that they don't lie, at least not successfully. You can't fudge your experience or hide your age, because your connections know you in real life. So Hoffman is inclined to agree with Thorpe's advice: Post your photo. "A LinkedIn profile lets you represent yourself as strong as you can, so build that to your advantage," he says.
Okay, but how do you finally land a job? It's the last question that Thorpe's students ask as he wraps up his lecture. Thorpe turns back to the elaborate diagram on the board, pointing to the circled numbers. Social networking is just a more efficient way of reaching out to people you know -- and people they know. You work the network. You connect with people like John Campagnino at Accenture if you want a job in consulting. Then you turn off the computer, and you call your connections on the phone. And you invite them to lunch.