Rich Barton — Mr. Vertical — has added a new recruitment-oriented vertical to a lineup that now includes Expedia (sold), Zillow and Avvo. The new effort is Glassdoor.com, which provides recruitment-related information. It solicits and publishes detailed salary and bonus information by position and company, as well as in-depth reviews about company culture and views of top executives.

The company was founded by Barton, former Hotwire President Robert Hohman and Tim Besse. Hohman and Besse worked under Barton at Expedia. The site has received funding from Benchmark Ventures and its founders, and has an initial team of 12 people.

Hohman says the company has launched with 3,300 reviews on 275 companies, mostly oriented toward the tech communities of Silicon Valley and Seattle. Eventually, it will add more universal categories, such as nurses and teachers. Everything on the site is free and (theoretically) supported by targeted advertising from employers and recruitment agencies, among others.

The first round of reviews was conducted by a research team and is already fairly representative, with a broad swath of job types. Each participant was promised anonymity, and received detailed information after providing answers to 16 questions in eight categories.

Some initial findings showed that Google pays engineers $110k, or $5k more than Microsoft. Apple, meanwhile pays its engineers $89K. People may work there for the prestige, says Hohman. At the Apple Store, meanwhile, the smart people who provide sales help get $9 to $14 per hour, while Geniuses behind the counter get up to $24 per hour.

The majority of initial reviews were for Microsoft, Yahoo!, Cisco and Apple. Microsoft people give CEO Steve Ballmer a 68 percent approval rating; Yahoo! people, meanwhile, give Jerry Yang 58 percent. Looking at the tracking, you can see Yang’s approval ratings really dived after he didn’t go through with the Microsoft sale.

While Hohman concedes that such a system could be abused, the site has worked to minimize it with safeguards, such as validated e-mail, implemented on the advice of Stephen Kaufer, a board member who was the founder of TripAdvisor.

Already, there are plans to syndicate content from the site around the Internet, and Hohman doesn’t rule out partnerships for recruitment with newspapers and other media, a la Zillow. But the site is primarily a destination site that will live or die on advertising, he says.