This is as easy as it could be:
For some users it might be easier to send you files via emails. Or they are just used to do it like that.
So every Wok comes with a dedicated email address. Instead of the URL just share the email address with you uploaders and they can upload into your cloud just by sending you an email with attachment.
The attachment is uploaded to the linked folder in your cloud. The message itself is forwarded to the email you maintained for notifications and messages.
All attachments are replaced be filenames and links to the uploaded files into your cloud. Thereby you'll save a lot of storage in your inbox.