This is a great article acknowledging not only the fact that librarians have been moving toward attracting the Millennial Generation for years, but the positive response that this generation has developed as well.
One of the main points is that the Library is not a Static Environment. The Library has always been developing, remember to move with the times.
The Dewey Decimal System is based on what is commonly thought of as ‘Bookstore’ organization method; though often librarians do not think of it that way. We can easily add signs, 200-300 is religion, why not label it that way? 910-920’s (approximately) cover the Travel section, we can label that as well.