The next time you see an article about a company or product, consider this: it’s possible the author heard about it through a Facebook ad.

Marketers, public relations companies and advertising agencies are increasingly using social media to carefully place messages in front of journalists and media professionals, in the hope that doing so will “earn” them or their clients coverage, or at least keep them top-of-mind for a mention.

This concept of targeting ads to “influencers” in certain fields is not a new one, but marketers say the increasingly granular targeting tools being offered by companies such as Facebook and Twitter are allowing them to get more sophisticated with their efforts.

It’s not uncommon for companies to target tailored messages to journalists at specific outlets such as The Wall Street Journal, the New York Times or USA Today, experts say.

For example, Wall Street Journal reporters have recently found themselves targeted with messages from companies including phone sanitation company Phonesoap and dietary supplement firm Herbalife, specifically because they work for The Wall Street Journal, as noted by disclosures that accompany Facebook’s ads.

“It works. You can get your messages out to incredibly specific people who you know can help you in myriad ways,” said Marty Weintraub, founder of digital marketing agency aimClear.

Mr. Weintraub said his company has already been targeting journalists with ads on social media sites for a few years on behalf of its clients, but he believes the practice is growing. What’s more, he thinks it can be a more elegant and effective way to get the attention of journalists and media professionals than bombarding them with emails and phone calls.

Targeting ads to people who work in media can be done in a variety of ways, the most simple of which is using the features now baked into the ad platforms of many social networks. Facebook, for example, allows marketers to target ads to people who work for specific companies or in specific job functions, based on the information they place in their profiles.

A marketer might therefore choose to target ads only to those people who work at The New York Times, The Wall Street Journal and the Financial Times. Further, they might opt to show ads only to people at companies Facebook deems to have an interest in journalism or news.

“I would imagine most public relations people who know what they’re doing would be doing this,” said digital marketing consultant Aaron Zakowski, who has also employed the tactic in the past. “To target journalists is pretty easy,” he said.

Another method is to use the email address targeting features now offered by companies such as Facebook and Twitter. A marketer might compile a list of email addresses of journalists concerned with a specific subject and use it to target only those users with their ads.

According to Mr. Weintraub, the tactic can be a good way for small companies that can’t afford expensive public-relations firms to compete for the attention of journalists and editors.

“It’s an inexpensive amplification device,” he said.

Write to Jack Marshall at Jack.Marshall@wsj.com