Think about it carefully. Do you adopt a totally different persona or voice when it’s time to market and promote? Of course you might put on your marketer’s hat to brainstorm ideas about marketing strategy, but those ideas ought to be expressed and executed by the “real” you, not a stilted, rational, or smarmy marketer version of you.
Modern hyper-connectivity means you will be screen-to-screen with your readers (and fellow writers) in a way that has never been possible before. This produces the kind of cross-skill crisis often seen in the IT industry, where a great programmer is suddenly promoted into a managing role. Suddenly your little private world becomes a hubbub of human relations and expectations management. Sound familiar?
I could give dozens of examples, and show you how an author’s unique personality directly plays into their marketing and platform building approach. However, easier said than done. Why?
Why indeed? Have a read of what Jane recommends here: http://writerunboxed.com/2012/05/25/what-authors-seem-to-forget-about-marketing-especially-those-who-dislike-it/