Over the past year of using both Dropbox and Google Drive to send files and folders to clients and consultants we work with I've encountered some strange things.
Usually it's someone who can't comprehend the fact that the file isn't in the email and subsequently has problems with clicking on the link and not understanding that they have to download the file.
I think both Drive and Dropbox ask people to sign in when they click a shared link which is annoying and unnecessary. But where Dropbox has the edge is when you go to download you can either save the files to your personal dropbox or download the files as a zip file.
They give you the choice! Imagine that!
But Google Drive just says "Open in Drive" which completely confuses people who don't use or have never heard of Drive. There should be another blue button beside it that says "Download".
They have to slowly ease people into this new world order of cloud storage rather than force them to learn how cumbersome it can be.