I suspect that Scribd may be good for precisely the kinds of proprietary format documents you don't see as YC news items very often (Word, Excel, PowerPoint etc

I suspect that Scribd may be good for precisely the kinds of proprietary format documents you don't see as YC news items very often (Word, Excel, PowerPoint etc). However for PDF, Scribd really isn't a good fit since there are already so many good PDF viewers out there. In particular the PDF support my OSX Laptop comes with blows Scribd out of the water so a Scribd link to a PDF is effectively a downgrade for me. Too bad there isn't some info in the HTTP protocol Scribd could use to decide to deliver me the PDF instead. Oh wait...