Graphics tell a lot story in a short amount of space. It’s descriptive without being prescriptive. For some fun examples look at http://thisisindexed.com/. It’s a blog that Jessica Hagy has diligently been posting since 2006. She hand-draws simple graphics that provide a lot of humor, and a surprising amount of truth. She also blogs for Forbes here and has a super affordable book here (affiliate link).
Venn diagrams are basic and boring. It simply shows the overlap of two sets. It’s not the most persuasive or interest graphic, and yet, look how much these pictures say. These were all drawn in August 2006. You can click on the pictures for the backlinks.