For two professions so committed to meeting the needs of readers, publishers and librarians have distinct cultures. Put simply, one culture is all about developing and selling books; the other is about sharing them and fostering a culture of reading. But there is another basic difference, too. Publishers work closely with authors and use sales figures to tell them what readers want, interpreting those figures like tea leaves. Librarians work closely with readers, using them as informants to help them select books that will satisfy the diverse tastes of a community. Though publishers and librarians may have different cultures, they have a common goal. S.R. Ranganathan put it in a nutshell with two of his famous rules: every reader his book; every book its reader. In an era when publishing opportunities have proliferated and the number of titles being published has skyrocketed, libraries rely on professionals who can do the painstaking work of developing quality books. In turn, publishers need librarians, who help spark a love of reading among children, sustain it through the stages of life, and know what is important to readers. Though book sales have slumped in recent months, library circulation is soaring. If publishers did not get the importance of libraries before, now is the time to get the message, because it is in libraries that book culture will be sustained through these hard times.