Why this is better than a syncing approach is not clear to me.
I was hoping the "new spin" would be something a little more radical.
An example: if I have a 320GB local drive and Dropbox keeps all its files on my local drive, I can't store the full 1TB of files in Dropbox that I'm paying for. However, I probably don't need all of those 1TB of files at the same instant, just various subsets which change over time, meaning that a cloud storage solution which doesn't require constant client-server sync lets me actually utilize the full volume of the service.
https://blogs.dropbox.com/business/2016/04/announcing-projec...
On serious note it would be very nice to have a choice in dropbox about what stays locally and what is cloud only. I don't understand those things that well but I suspect it would be relatively easy for them to add that if it's becoming a selling point for the competition.
They must think they have more potential selling points if they are getting 77M.