It would be nice if there was a folder in Google Drive which, when new PDFs were added there they would be observed by Paperpile and automatically imported. Perhaps offering the user to review the imported items upon the next time they login. This is especially useful for people who might use other apps that sync with Google Drive, like GoodReader.
That is a good idea. As a new user I missed the option to have a watched folder that is available in other softwares.