"Why not? As I said, it is your money. You have earned it honestly; you may spend it honestly."
Jackson was staring at McLeod, but he said nothing.
"Tell me, sir," McLeod said, "how does the success of my book compare with the success of most books in the galaxy?"
"Quite favorably, I understand," said the Resident. "The usual income from a successful book is about five thousand credits a year. Some run even less than that. I'm not too familiar with the publishing business, you understand, but that is my impression. You are, by Galactic standards, a very wealthy man, professor. Fifty thousand a year is by no means a median income."
"Fifty thousand a year?"
"Yes. About that. I understand that in the publishing business one can depend on a life income that does not vary much from the initial period. If a book is successful in one area of the galaxy it will be equally successful in others."
"How long does it take to saturate the market?" McLeod asked with a touch of awe.
"Saturate the—? Oh. Oh, I see. Yes. Well, let's see. Most publishing houses can't handle the advertising and marketing on more than a thousand planets at once—the job becomes too unwieldy. That would indicate that you sold an average of a million copies per planet, which is unusual but not ... ah ... miraculous. That is why you can depend on future sales, you see; over a thousand planets the differences in planetary tastes averages out.
"Now if your publishers continue to expand the publication at the rate of a thousand planets a year, your book should easily last for another century. They can't really expand that rapidly, of course, since the sales on the planets they have already covered will continue with diminishing success over the next several years. Actually, your publishers will continue to put a billion books a year on the market and expand to new planets at a rate that will balance the loss of sales on the planets where it has already run its course. Yes, professor, you will have a good income for life."
"What about my heirs?"