NEW YORK ( TheStreet) -- The online recruiting firm Jobvite.com says 75% of American workers are either seeking or open to new career opportunities. This itch to move is no short-term phenomenon, but a culture of "constant job-seeking" that is another cog in the notorious "new normal" economists and sociologists talk about. One-third of U.S. employees say finding a job is more difficult today than a year ago, the firm says, and 41% of U.S. workers believe they are "overqualified" for desired jobs. But that's not stopping them from thinking of making a change. How can job-seekers stand out in such a competitive environment? Jobvite says that social networking sites are a huge hit with employers and employees (and job-hunters). Facebook ( FB) is the No. 1 social networking site in the U.S. for job-seekers, with an 83% adoption rate among them. Twitter and LinkedIn ( LNKD) are coming on fast, though. Twitter is now used as a job-hunting tool by 46% of workers, as opposed to 37% last year, and LinkedIn saw its adoption rate climb from 32% to 41% on a year-to-year basis. "With fierce competition for jobs, which now includes a majority of employed people on top of active job-seekers, social media has become a critical tool for job hunting and career growth," said Dan Finnigan, president and chief executive of Jobvite. "One in six job-seekers polled credited a social network for leading to their current/most recent employment. Maintaining your online presence and keeping employment top-of-mind at all times are vital to professional success. With technology and social networking rapidly evolving, those who don't engage through Facebook, LinkedIn and/or Twitter will quickly find themselves falling behind." How can you leverage social media to improve your job and career prospects? It's surprisingly simple to do, while not doing anything to upgrade your social media presence can really work against you. Scour your profiles with a fine-toothed comb: Jobvite says 86% of employers and recruiters are "likely" to search social networks for job candidates, and a vast majority of hiring decision-makers say spelling errors and profanity are big negatives. So keep it clean. Play up your career connections: Make it a habit to mention any links, memberships or affiliations with professional organizations or industry associations. According to Jobvite, 80% of recruiters "like" to see links to professional groups, yet only 20% of employees post that data on Facebook, Twitter or LinkedIn. Steer employers to your Facebook page: Only 17% of employees mention their Facebook page to employers in resumes, cover letters or on job interviews. Big mistake. Recruiters and employers love forward-thinkers, and having your own Facebook page - dedicated to your career - separates you from the pack. "Google Me": Make sure to check Google and see what pops up when your name is popped in. Why? Hiring managers seek candidates who are highly visible in the public domain - it shows you're active and aggressive about your career, two traits companies love. But if companies can't find you, they may view you as being too private. Worse, they may think you have something to hide. Be steady on Twitter: When it comes to Twitter, be a "Goldilocks" Tweeter. You want to reach a balance of steady, uniform tweets on your industry and on career-oriented passions. Again, keep your tweets clean and direct and provide links to support any of your stronger opinions. Too few tweets makes you look less engaged or indifferent. Too many and an employer will wonder how you can get any work done with all of those tweets you're sending. Some personal tweets are fine - employers love to see the personal side, too. Facebook, Twitter and LinkedIn are great ways to promote you to hiring decision-makers, but only if you manage your social networking persona right. Do that, and you'll stand out from the crowd and improve your career standing in the process.