I doubt all writers are introverts but I bet many are. I think to myself that I could handle doing blog posts. Social media. Virtual chats. All that. That is about it. I am a hermit. My computer is my way of contacting people. I can do marketing online, but the in person thing? Not so much. Right now not an issue with e-books.
I slack on the marketing as it is to be honest. It is just not something I excel at. That has to change somehow or I will get nowhere fast. So I decided to put my latest book at the bottom of my posts in an unobtrusive fashion as a sort of advert. Not sure if it will work, but giving it a go. I would rather not always post about a novel I have published and this seems to be a good compromise. Let me know what you think, since I tried it out here.