I'm surprised the more logical combination of adding a "Print with Lulu" button to iPaper hasn't been added with commission for each sale going to Scribd (and possibly, in the future, the original author of the document so the platform could be used for previewing books from small-time authors).
The ability to instantly get a PDF printed and mailed to you via paper would be a nice feature.
Or, you could just, like... print it on your own printer. You know, just sayin'.
I guess it would be useful if you don't have a printer, but then shipping, etc. would make it kind of pointless, with the obvious exception of books (or other documents) on Scribd that have a certain production specificity.
The ability to instantly get a PDF printed and mailed to you via paper would be a nice feature.