...and 5 Possible Answers:
PosterityThis is the easiest to deal with, because posterity doesn't care. In fact, posterity may never happen (although it probably won't end quite this soon).
So, no pressure, take all your life. And since you have no audience, you can experiment. Be yourself; think weird, allusive and outrageous.
P.S. Most poetry falls in this category.
YourselfAgain, no pressure. Follow the instructions for Posterity above. (This may be something your psychiatrist has told you to do).
Friends and FamilyApplies to memoirs, family histories and the one book we are told (often erroneously) that we all have buried inside us. There’s a bit more pressure on selling for this one, but once you have ditched 20 at £60 a copy to relatives who hope it will get them a mention in your will, you stop.
To Impress (a Girl)You may want to substitute genders, but this is high up the personal satisfaction list. A long time ago men wrote, then dedicated lives and books to their muse (who was, sometimes, another man). The essential aim was to woo, marry or seduce the woman in question, but many have used the notion as a springboard for the imagination.
Again, this works best, but not exclusively, for poetry.
MoneyFame etc., the BIG ONE. This is what most of us aspire to. Whether it's to make a living without having some jackass boss shouting in your ear all day, or to buy that yacht you saw once in Casino Royale, writing for money is the biggest challenge of all.
And it's the one you need to prepare for if you want to MAXIMISE your sales.
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