SAUSALITO -- Fueled by millions of new users in the past year using its website, social media tools and mobile apps to get and give a transparent look inside companies before the job interview, 6-year-old Glassdoor is taking a big step toward accommodating its growth.

[caption id="attachment_77651" align="alignright" width="360"] Paid enhanced employer profiles allow companies to customize how they look for job-seekers.[/caption]

Glassdoor (415-339-9105, plans to move in early January into 30,350 square feet of office space in Shoreline Office Center on Richardson Bay in Mill Valley. Currently, the company has most of its 170 employees in 18,000 square feet of "cozy" quarters in Sausalito and has openings for 20 more, particularly software engineers and salespeople.

"Growth has been surging," said Samantha Zupan, director of corporate communications. gets 13 million visitors a month and now has more than 20 million member accounts for those seeking the latest job listings and wanting to find out what working at a particular company is like, what interview questions they ask and how much they pay. A year ago, there were 10 million members.

In the past year and a half, Glassdoor has launched the Facebook app Inside Connections to allow job-seekers to connect with other users of that social network to learn more about a company, apps for Apple iOS and Google Android smartphones and tablets, and Employer Center, an emerging set of analytical tools for employers to discover trends among candidates and employee reviews plus offer their own company information.

While the member accounts and Employer Center are free features, Glassdoor earns its paycheck through job listings and recently introduced "enhanced company profiles." With a free account, companies can update basic information such as number of employees and current chief executive plus get aggregated demographics of candidates. Starting at $600 a month, depending on employee count and page traffic, enhanced profiles allow companies to spruce up the Glassdoor page job-seekers use to learn about them with branding and what sets them apart from competing employer choices.

So far, more than 800 employers have signed on as customers, including San Rafael-based Autodesk as well as Amazon, Nordstrom and Spotify. Revenue has grown by more than one and half times in the past year.

[caption id="attachment_77652" align="alignnone" width="500"] A new Employer Center allows companies to see trends among candidates.[/caption]

It took some convincing for employers to see the value of Glassdoor, but the company-sponsored research suggests it could be worth it. Candidates for jobs in 10 industries were 22 percent less likely to leave a leave a job after being hired because they were better-informed about what to expect after starting work, according to the study.

Glassdoor has garnered believers among investors as well. Started in mid-2007, the company has raised $42.2 million so far, most recently raising $20 million in October from DAG Ventures in Palo Alto and existing investors Benchmark Capital, Sutter Hill Ventures and Battery Ventures.

Whitney Strotz of Cassidy Turley's San Rafael office represented Shoreline property owner Equity Office Properties in the late June lease to Glassdoor, which worked out a deal to shift from One Harbor Drive in Sausalito, another Equity Office property. Laurence Morgan and Jon Wittemyer of CBRE represented Glassdoor.