Good communicators are leaders because they know how to give their audiences what they need. To paraphrase the Jack Welch quote, they become leaders because they grow themselves as they work to grow others.
The success of personal finance gurus, who inject personality and brand into their advice, telegraphs a deep level of knowledge and intuition about how their audience thinks and feels about money. That has big implications for how you deliver your message as a speaker or a thought leader.