Share for commenting online

I am trying to find a way to share a PDF online for review and commenting, and cannot seem to find a way.

Acrobat Reader DC  - Send & Track allows me to share a document for viewing and download. But no way to allow comments on a single document (you still end up with multiple downloaded copies)

Creative Cloud allows me to share a document, and provides a "Comments" field below the preview... but this is really not very intuitive. I really need to allow commenting using "Sticky Notes" or other more annotative tools.

Am I missing something?