Ask HN: How much does a master's degree matter, in addition to a bachelor's?

I'm curious as to whether I should spend another year in school.

1. Will getting a master's degree improve my job prospects, both in terms of hiring and of salary?

2. Will spending another year learning about more topics help me on the job and in my own endeavors, or is it better to learn in the industry? e.g. take a course on machine learning for a master's, or self-realization about the subject while working on a machine learning project?