Lots of freelance writers use social media — LinkedIn, Twitter, Facebook and the like — as a way of finding clients, finding sources, and staying in touch with other writers. But I think few are aware of the emerging writing niche of getting paid by companies to write on social-media platforms.

The most basic social-media jobs involve writing Web content or doing social-media strategy for corporations, helping them with their social-media presence. Many companies are at the stage where they know they should be in social media, but they don’t really know how to do it, and they are turning to outside experts. It’s sort of a gold-rush moment in the field, since it’s still an emerging medium.

If you’ve been using social media yourself — you’re blogging and posting on community forums and major social sites, or running your own niche site and optimizing it for search — you should realize you have expertise that companies are paying for.

Because it’s such a new field, pay is all over the map. You can tell it’s starting to be a real job niche, though, because niche job Web sites have already sprung up to aggregate these jobs, such as jobsinsocialmedia.com. Recruiter Jim Durbin, the site owner, says pay depends mostly on your credentials and job history. If you’re a brand-new writer with your own blog, you’ll probably start out not making much. If you have copywriting experience or an agency or big-company marketing background, you could find yourself making $120,000 a year in a social-media strategy job.

Recent trends on Indeed.com show jobs that include the phrase “social media” in the description have gone from basically nothing a couple years ago to nearly 1 percent of all jobs listed on the site! I got more than 18,000 job listings for that keyword on a recent search, many for major companies including Radio Flyer, Avis, Hewlett-Packard, Coca-Cola and Office Depot. Big nonprofits including World Vision are looking, too.

Here are some of the major jobs in social media and descriptions of what they do. Maybe there’s a great new area in writing for you to help grow your income.

• Blogger. Most writers are familiar with blogging by now, but may not realize that companies and publications are paying well for blogs. Personally, I made more than half my income in some recent months from blogging for companies and major publications. Pay ranges from squat to more than $100 a post.  To earn more, think about specialized, unusual expertise you can leverage, and target bigger companies and publications that need to project a top-quality image.
• Community manager. I wrote recently about my cool friend Tony Kehlhofer, who landed an amazing part-time, work-from-home gig as a community manager for Lego’s new massive multiplayer online game for tweens, Lego Universe. You can read over there about the training he got so he can now monitor and respond on behalf of Lego to kids as they’re playing the game. I talked with a recruiter recently at a division of Spherion for my AOL story who said he’d recently filled a similar full-time community manager gig for a big company that paid $120,000 a year. Generally, if you’re already making a big-time marketing salary,  you can command these kind of rates.
• Social-media strategist or digital strategist. If you’re someone with a LOT of social-media experience, who understands what works and doesn’t in drawing people to a Web site, you can earn big in this role. Social-media strategists often oversee a social team developing on a company’s online marketing strategy. This person decides what the company needs to be doing in social media — what messages they should be sending, what sites they should be active on, the works. Copywriting coach Chris Marlow says most of the work is still freelance — but it’s going for upwards of $200 an hour. Working under this top-dog can be social-media marketing specialists and associates who help execute the strategy, tweeting, setting up Facebook fan communities and keeping them active, and so on.
• Online customer service representative. This can be a bottom-rung place to get started. It’s like the social-media version of a call center worker. Online reps troll social sites for mentions of their company, and then respond if needed. Had an interesting personal experience with this recently — got to jawing on Twitter with another writer about taxes and how we’d gotten IRS notices. I mentioned TurboTax didn’t seem to know how to do the adoption tax credit, I’d gotten a revision letter both the years I took it using the software. Next thing I know, a TurboTax rep DM’d me on Twitter to ask if I needed help! I told him about the problem and he said he’d report it to the company. What a feel-good customer experience! Somebody got paid to reach out to  me on there…and you could, too. These folks are also sometimes known as “online reputation defenders,” crusading online to burnish their brand’s image.
• Search engine marketing associate. SEM associates work with a Web site to make sure it’s optimizing its results in natural search on Google and other engines. Some of you are already doing this for your own sites, and could apply what you know to a paying gig.

PS: Want to learn how to effectively use your social media to consistently sell more books, gain more followers and grow your author brand WITHOUT using ads or feeling salesy? Make sure to check out Self-Publishing School’s mini-course on Social Media for Authors!