What advantage in your job search would be offered by getting a master's?

I know some management consulting firms like applicants with advanced degrees, but typically in cs/business not pure CS.

Even then, I might recommend getting your foot in the door and hopefully getting your employer to pay to continue your education.

The only other motivation that comes to mind would be a burning question you needed to research and answer for yourself. Perhaps though that would be motivation to explore a PhD rather than a master's.