[thomnific]

I would echo another comment here and say that it depends. However (speaking from my own perspective) depending on the discipline there's no specific need to do a PhD in order to understand and apply machine learning.

It also depends on what you mean by "advanced degree". I have an undergraduate degree in physics/math and a master's in economics/finance, and I find between those two things I've been able to follow developments in machine learning and also to apply them to my work. In fact, I used to get a bit annoyed with those who would imply that I "must" do a PhD ... I would say that's certainly true if I wanted to invent new estimators etc., but otherwise not so much. A PhD can be great for other reasons but it's not the sort of thing required for actually doing my job.