Is Glassdoor a juggernaut disrupter of the recruiting industry, an online watering hole for disgruntled employees, or a de facto pay-to-play scheme for entrepreneurs? Depending on your Glassdoor rating, it may be all of the above.

The Sausalito, California, job-review site was founded in 2007 by a trio of Expedia veterans. Their idea: Provide an anonymous forum for employees to dish on companies, bosses, and salaries, and distill scores down to an easy, five-star system.

The company's early days were heady in typical Silicon Valley fashion, with free-flowing office booze, team treasure hunts around San Francisco, and "an absolutely fun culture," according to former senior account executive Cody Arabia. The startup actively encourages its employees to review that culture, and perhaps not surprisingly, it aces its own tests: Glassdoor the employer registers a 4.7 score and 99 percent CEO approval rating on Glassdoor.com.

It's had external success too, earning nearly $93 million in venture funding and a reported valuation of close to $500 million, setting it up for a potential IPO. It's become the first stop for pretty much any job searcher or salary negotiator--and it's also chock-full of unverified, exaggerated, and just plain fabricated information. Membership is free, and checks on users' identities are imperfect at best; Inc. has confirmed that it's possible to create multiple accounts under fake names and to post critical reviews of companies where the writers have not worked.

Glassdoor can initially appear to give "a good picture of what salaries are looking like, but it does not verify the representations people make," says Nick Corcodilos, a recruiter who runs the Ask the Headhunter site.

Glassdoor says it does what it can to police its user-submitted reviews: A content-management team, based in Ohio and Sausalito, screens reviews and weeds out posts that include obscene or threatening language. The team rejects up to 10 percent of submissions "because they don't meet our community guidelines," says spokesperson Samantha Zupan. But "how do we know these are the people that they say they are? We don't. It's a crowdsourced site."

Weeding out fake information is a challenge for any anonymous review site--just ask Yelp, Amazon, and TripAdvisor. But as on Yelp, which has been sued repeatedly for allegedly demanding that businesses pay to have negative reviews removed from its pages (Yelp denies the charges), those fake reviews play into Glassdoor's business model, at least inadvertently. The company won't discuss its revenue in detail, but says that most of it comes from selling job ads and analytics to monitor a business's reputation--and from offering paid, "enhanced" profiles to companies looking to polish their listings.

Hence the grumbling from business owners, some of whom see Glassdoor's pay-for-placement methods as a veiled threat.

"To me, it's like a ransom," says Robb Fujioka, co-founder of tablet-maker Fuhu and an unhappy buyer of a Glassdoor enhanced profile. Fuhu's rating remains a dismal 2.1, based on 70 reviews. "They should be offering up account representatives to address untrue facts for free," he says. "Why would you pay for enhanced services otherwise?"

Glassdoor allows all employers, even those without paid profiles, to respond to reviews--and "if you use our paid products, we do not take down reviews or other user-generated content because you are a client," Zupan says.

Others are happier with Glassdoor's results. "It's been a really effective recruiting tool," says Glenn Humble, the director of marketing at Adroit Digital. The marketing agency's parent, MediaMath, has an enhanced profile--which shows off a 4.5 score--and now Adroit is considering buying one. The "great draw" would be adding a video component to Adroit's page, Humble says. "The downside, of course, being that it's paid."

Lindsay Blakely contributed reporting.

From the Dec 2014/Jan 2015 issue of Inc. magazine