That's the job of the aspiring writer. Well, the job of an aspiring writer who wants to be published.
Even if you ignore the merits or otherwise of ebooks or print, self-publishing or publishing corporation, at the end of the day you - the writer - have to sell the book. And first of all, that means selling you.
It is not something I am naturally gifted at. Many people are, prepared to speak out and promote their own ideas... or force their opinions on us, the unsuspecting audience. Often such people come across as unpleasant: arrogant, only concerned with themselves. Yet (and I hate to admit this) they also often get things done. They get to where they want to be. Sure, they probably have some talent in their chosen field, but much of their success is due to self-confidence.
I know: I've watched The Apprentice.
Some of us are more reticent and don't blow our own trumpets. I find it so difficult to say anything positive about myself without immediately apologising afterwards. Yet why should I? Though I have many (many, many, many) weaknesses, I'm not all bad. In fact, bits of me are quite good. (Quite, you note.)
This week I sent off my book to an agent. Just the one (it took me all day to prepare for and build up the confidence for that!) Writing a cover letter that sells me and the book is difficult. Writing a cover letter that boasts without being overbearing is difficult. Writing a cover letter that shows you know your market and love writing and have an exciting opening and are the best person in the entire universe and just what the agent is looking for ... is difficult.
Have you guessed what I found hard? Nevertheless, I hit the 'send' button and now await with bated breath. I anticipate a long wait...
[Incidentally, I found the service BubbleCow offered really helpful. They give lots of free and friendly advice: go look them up! I've also perused hundreds of blogs and picked up tips from other writers. I'll let you know if any of them work!]