i realize it might be slightly out of scope, and a less common use case, but an FTP integration that worked the other way around (users can upload to a filepicker hosted FTP and it sends a postback to my app) would be enough to get me to subscribe. cool service.
They actually do this via S3, user can upload a photo to Filepicker S3 and then sends a post to your app with the URL of the image. You can then download the image onto your own server, add text captions to it, resize it, whatever you want, using GET parameters.
this doesn't help the use case where i have a client who would prefer to upload files through FTP. but, nice to see it's not out of the realm of possibility.
So services in the education market (like Blackboard and others)seem to depend heavily on WebDAV for integration school systems. That's one fo the reasons why we chose WebDAV.