I think Safari's content has a greater value density than Audible's. For example, I've been referencing a half dozen textbooks the past month or so on theory and implementation of risk models for the insurance industry via Safari. The information I've learned from some of these books is easily worth $49 and then some.

I could imagine someone learning to code for the first time might find better value elsewhere with that $49 a month, but in my case I think that it works out.