As per Scribd's FAQs:
Scribd lets you publish and discover documents online. It is like a big online library where anyone can upload. We make use of a custom Flash document viewer that lets you display documents right in your Web browser.
Part of the idea behind Scribd is that everyone has a lot of documents sitting around on their computers that only they can read. With Scribd we hope to unlock this information by putting it on the web.
Scribd would a useful website for students, especially, graduate students to get feedback on term papers, thesis or dissertation chapters, and for providing feedback to other users. For professors Scribd could prove helpful in publishing pre-publication documents for feedback or learning about what other college instructors are doing in their field or another field.
Over the past couple years Scribd has steadily grown in its users and readership. Please take a look for yourself and see what you can share or discuss.