Can you make money from an email list?

Is it really possible to generate income from an email list? I've heard mixed opinions on the matter, and I'm curious to know if there's a proven strategy or set of best practices that can lead to financial success through email marketing. Could you elaborate on the potential revenue streams and how one might go about building and monetizing an email list in the realm of cryptocurrency and finance? Additionally, are there any potential pitfalls or ethical considerations that one should be aware of when pursuing this path?