I'm genuinely curious how many people you find to like markdown, once you are outside the tech community. My work has always focused on detailed content management, which isn't Markdown's strength (nested lists, embedded tables, detailed options on layout and numbering, etc.), and markdown is therefore a non-starter when we talk about putting authoring capabilities into our customer's hands. I can see where email is simpler, so the tech limitations won't stop you.... but would love to hear what audience/demographic is paying for a service where markdown is the main feature?