Edelman and LinkedIn have done some research on what works with Thought Leadership. Some of the findings are quite surprising. Not least, that brevity itself is highly valued.
Other things that are called out (see text below or slide 21 for a graph in this SlideShare) are the source and the content's relevance. Relevance is a given but the interesting thing is that the "source" is not the Author, it is the individual that forwarded the content.
What this means is that sharing short, timely industry insights written by your team with your prospects is the best way to help them through thought-leadership.
Obviously, I could say a lot more about this but I'll keep it short...