Social networking site Facebook is just as popular among its employees as it is among its users. The Silicon Valley start-up was named the best U.S. employer on Wednesday by employment website Glassdoor.com, which conducted a survey among its users.

The company was so small last year that it did not even feature on the annual list, which was topped by Southwest Airlines in the past two years.

But Facebook has been growing rapidly by poaching employees from rivals like Apple and Google.

Besides offering handsome salaries and princely benefits, Facebook also offers employees the real prospect of becoming millionaires when the company, which is valued at $43 billion, goes public. Many employees have already joined the elite millionaires’ club by selling their shares in the company to private investors.

No wonder then that chief executive Mark Zuckerberg, who was named Wednesday as Time Magazine’s Person of the Year, was almost universally liked by his company’s employees, who gave him a 95 per cent approval rating. Facebook’s overall satisfaction rating among employees signed on to Glassdoor was 4.6 out of 5. Just behind Facebook were Southwest Airlines, with 4.4 out 5, and Bain & Company, with 4.3 out of 5.

The Glassdoor survey was based on eight criteria including work/life balance, recognition and, of course, compensation and benefits.