ability to upload PDF documents
I have a suggestion to upgrade your software beyond premium say VIP where your software would enable or provide the user the ability to attach PDF, jpeg, word any kind of document upto a certain file size limit say 10 Megabyte. This is the size limits for emails in most Australian ISPs (internet service providers).
This would also stop heavy end users attempting to upload large digital movie files etc.
You could call it TOCOLLABORATE or TODOCLOUD.
Best wishes with the software.