Although this isn’t widespread public knowledge yet, it is apparent that the next round of usage patterns around services such as Dropbox and Google Drive are going to be determined by how you collaborate.
Dropbox’s purchase of the service Mailbox was a dead giveaway that storage sync alone is no longer relevant. It did serve well to get Dropbox going. Another signal is Google Apps’ integration with Google Drive. Every time you send an email from within gmail with a Google Drive link, gmail will invoke a permission check (what all could they be checking for?).
My own usage patterns are getting clearer. I now prefer to use Google Drive as the collaboration feature around documents. This way I ensure that the receiver need not have a client. For an upcoming event I’d sent out questionnaire’s using Google Drive to the participants. I then shared the complete questionnaire’s with the panelists to help them prepare. The last time I did something like this with Dropbox I had to convince the receivers to install it. Convenience at play?*