After a while the business end of writing takes too much of the writing time. Better to pay someone ten percent and find that you're still more than ten percent ahead in the end. Which is true. My present agent says that he always feels that a good agent during the course of a year should earn back for his client at least the ten percent he takes by way of commission, so the client's really nothing out. And what he should ideally do is make him more money than the ten percent.