SOS Online Backup is a cloud service like Google Drive or iCloud, but it features optional enhanced security and unlimited storage space.
Optional client-side encryption: Most cloud backup services keep a copy of your encryption keys. With client-side encryption, only you know your account password, which increases your privacy.
Local backups: SOS can put a mirror image of your cloud files on an external hard drive or USB stick, for offline use and extra backup.
Real-time backups: You can enable specific files to be backed up every few seconds, even if they're in use.
Unlimited file recovery: When you delete a file in the cloud, or a local file that you have synced, you can opt for SOS to keep a copy of that file indefinitely. That way you can recover the file months later, if it turns out that you needed it.
Unlimited file versions: You can tell SOS to create an unlimited number of new versions of a file in the cloud every time you save it.
Unlimited file size: You can back up things like HD videos and virtual hard disk images without worrying about a cap on their size.
Global network of in-house data centers: SOS operates 11 of its own data centers around the world, rather than contracting a third party to store your files.
24/7 live customer support: You can get technical help via chat if you have a problem with SOS in the middle of the night or over the weekend.
Reasonable pricing: At $8 per month or $80 per year (or $140 for a two-year plan), SOS does not have the lowest prices. but you get a long list of important features. Being able to use PayPal is also a nice touch.
Limited iOS backup: iOS devices get full access to your files in the cloud, but you can only back up your iPhone or iPad's photos and contacts.
Limited trial: The 15-day free trial is limited to 50GB of storage, so you can't get a preview of how the service handles a large-scale backup.
If you don't need cloud backups of your iOS device, it's hard to beat SOS Online Backup's combination of features and price.