Online storage services all come with some standard access methods, such as web browser based file manager and mobile applications.
Some come with a synchronization folder. For example, Dropbox, SkyDrive and Google Drive all come with a synchronization folder.
For personal use, it may be OK for the web browser based file manager and the synchronization folder.
As online storage services getting more and more popular, personal use is gradually turning in to team collaboration over the online storage. Synchronization based accessing method gradually turning into On-Demand Access.
So customers don’t want the long wait time for the file to be synchronized to cloud. Instead, they want instant, on-demand access.