We're all trying to sell something, even if it's just our ideas. If we weren't, social media wouldn't exist and neither would the blog, the book or the portfolio.
This is why it helps when photographers learn to write and writers learn to photograph. And all of us are helped by learning to publish.
When's the last time you read a marketing book to improve your art? When's the last time you thought about how to best publish your work to sell your ideas?