... Measuring success.
John Stuart Mill, of all people, said that the difference between eloquence and poetry is that eloquence is heard, poetry is overheard. I think for the writer of fiction and poetry the first order of the day is to get it down right. Each such writer is communicating first of all to himself. But, since general rules of grammar and usage are involved, what is produced is likely to communicate to certain others as well - who, as it were, overhear it.