If wide-scale marketing had been around back in the days when manuscripts were available, it would probably have been difficult to keep up with the demand that marketing would produce. The art of writing manuscripts would probably have been more wide-spread than it was, and paper making would have been more of a lucrative field to dabble in. Marketing would have helped the book business, especially when other people could advertise in your books, as is common in newspapers and magazines nowadays. People would be more tempted to invest in books if their name and brand was in the book, and an decent-sized audience would have been able to access it. Marketing would also probably increase the demand for public libraries, where these books could be accessed on a larger scale. If marketing was around earlier, book technology would have been moved along more quickly, because demand “demands” it.

http://manuscripts.cmrs.ucla.edu/index.php