McMaster University Library is doing an interesting little thing with their catalog. They have become a member of the Amazon Associates program. Patrons searching for books in the catalog now see a small "Buy from Amazon.com" button at the bottom of catalog record. The library says that "faculty and graduate students in particular may appreciate the ability to review a title in the Library before adding it to their personal collections." Patrons still have the option of borrowing the book for free, the library has just added the option of buying the book as well. The Library benefits from by earning a small referral fee from Amazon on each sale. Amazon pays these fees through Amazon gift certificates. The library will use the earning to supplement additional book purchases.