For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Dropbox - Online Sync and File Sharing
Online Vault Backup - Online Vault Backup is a cloud storage service that allows you backup your data while having unlimited storage.
Google Drive - Access and sync your files anywhere
WholesaleBackup - WholesaleBackup is an online data backup service provider that turns your system into a backup server, allowing you to host the backup data on your own Windows Server environment.
Mega - Secure File Storage and collaboration
Rebel Backup - Rebel Backup lets you make encrypted backups of your important files to Dropbox or Google Drive.