Easy sharing of documents with clients or colleagues who aren't online at that moment! Great tool when you need it most - like during an emergency meeting call where no one can access Dropbox/Google Drive from home because their internet is flaky!! It's not as user friendly if your team doesn’t have much experience using cloud-storage websites (iCloud storage would be better).
But there are some tutorials available which help ease this process in case needed someday later down the road after more people use drop mark regularly over time :).