Well, it’s a pre-interview signal, like anything on a CV. Previous employers, alma mater, extracurriculars, yadda yadda. If I’m compiling a shortlist to interview, completion of a relevant MOOC from a quality provider such as EdX, the Andrew Ng course, etc, will increase the probability of them being on it. It’s not just the technical skill either, it’s the good attitude of starting and finishing something above and beyond normal duties.