How to help employees spill the beans and make money from it

JOB-SEEKERS fear that recruiters trawling social-media sites will find reasons not to hire them (why do friends always bring cameras to “50-Shades”-themed parties?). But firms should also worry that their secrets will be revealed online: some job sites ask staff to dish the dirt on their employers.

Glassdoor, for example, boasts employee-penned reviews of around 130,000 workplaces. (“Intellectually stimulating,” writes a staffer at The Economist Group. “Worst job ever,” gripes another.) Indeed, which claims to be the world’s most popular job site, started collecting reviews last year. Its users have scribbled over 1m in 2012 and are adding 200,000 each month.

Careers sites have traditionally shunned employer reviews, for fear of upsetting advertisers. But newer ones act more like search engines than job boards, aggregating vacancies already listed elsewhere. That makes them thirsty for unique content to set them apart from competitors, says Mike Larsen, who runs an Australian job site called InsideTrak.

Though they make less cash than their older rivals, these aggregators look sprightlier. Indeed claims 85m monthly visitors; the Japanese firm that bought it in September is said to have paid almost $1 billion. Glassdoor has 14m registered users, and in October raised $20m to expand.

Glassdoor requires all reviewers to make positive comments as well as snarky ones. About two-thirds of users report that they are satisfied with their jobs, says Samantha Zupan, an executive there. Those happy vibes please recruiters. Glassdoor lets firms sponsor their own pages on the site, or promote vacancies on those of poorly reviewed competitors.

Keren Mitchell, founder of TheJobCrowd, which focuses on graduate careers, says warts-and-all reviews help companies by weeding out ill-fitting candidates. They also make for better rankings of graduate-recruitment schemes: the researchers of these rankings often interview students about their preferences, rather than interrogating those who have actually started a new job. This rewards companies that spend a lot on marketing, not those that give new hires interesting work.

If review sites are holding employers to account, they may one day spell trouble for shirking staff. KarmaFile, a site based in Pittsburgh, lets workers rate their colleagues online. Mitch Turck, its founder, promises users the power to reject unfair assessments, provided they explain why.

This will make his site tamer than Honestly, a franker peer-review platform which critics said helped disgruntled workers bad-mouth bosses without their knowledge. It closed in May, having already once changed its name, from Unvarnished. As social media drag office life online, mismanaged firms and disagreeable co-workers may need a rebrand, too.