I don't know, that's one of the biggest benefits of Dropbox, I tell someone I'll add a shared drive and 9 times out of ten they already have a Dropbox account (in my tech world bubble at least)
Yeah, but some folks have come to the same conclusion as jacquesm ( above ) and use the big G as little as possible.
Sure, I have a google account. I almost never use it.
For me, the epiphany came when my adsense account was suspended years ago. For what I never found out. I appealed and was reinstated. I then pulled adsense from every site. Lesson learned, and I don't need to learn it again.
Presumably there is some software to be installed as well, but yeah I'm sure it's only a matter of time before the press releases of 170 million Google Drive users come out!