From: https://www.skylable.com

OPEN-SOURCE STORAGE
MADE EASY
UP AND RUNNING IN 1 MINUTE
Build your own S3 and Swift compatible object-storage
using commodity servers.
Increase security and performance, reduce costs.

From: https://www.pcloud.com/

Create a pCloud account and instantly get 10 GB free online storage space.

From: http://www.macworld.com/article/2915637/why-i-prefer-crashplan-for-online-backups.html

Most of these services can back up your data to local hard drives as well as to the cloud. But 
CrashPlan is the only one that offers peer-to-peer backups too: I set aside some space on my backup 
disk for your files, you do the same for me, and our Macs back up data to each other over the 
Internet, but without relying on third-party cloud storage. (Your data is kept encrypted the 
whole time so I can’t see your files, even when your backups are on my disk.)

From: https://www.backblaze.com/best-online-backup-service.html

There is no need to pick folders and files. Backblaze is the only cloud backup solution that backs 
up all your photos, movies, music and documents automatically. Of course you can also pick what not 
to backup in Backblaze Settings. Any deleted files will be retained for 30 days. Learn more.

Backblaze does not want to waste your bandwidth or Backblaze datacenter disk space. Thus, we do not 
backup your operating system, application folder, or temporary internet files that are transient and 
would not be useful in the future. Backblaze also excludes podcasts in iTunes.

From: http://www.maximumpc.com/best_cloud_storage_2014?page=0,0

  Some are ideal for security mavens who want to preserve their anonymity (and the anonymity of their data). Others 
  are better for folks just looking for a massive dumping ground for a ton of data. And still others are geared 
  toward those keen on sharing all sorts of files with their friends and colleagues. 

From: http://owncloud.org/features/

  Keep your files, contacts, photo galleries, calendars and more synchronized amongst your devices. One folder, 
  two folders and more – get the most recent version of your files with the desktop and web client or mobile app 
  of your choosing, at any time.

From: http://www.code42.com/crashplan/features/compare/

  CrashPlan Free - Offsite to other computers - Offsite backup doesn't get any friendlier than CrashPlan. 
  Back up to multiple offsite locations, such as other computers in your network of friends and family, 
  keeping your files safe from disaster at any one location.

From: https://www.surdoc.com/trybuy/viewplans/

 100 Gig Free; easy windows backup setup; special files do not backup like *.edb

From: http://pcsupport.about.com/od/software-tools/tp/unlimited-online-backup.01.htm

  Just Develop It (JDI) operates MyPCBackup, as well as ZipCloud, JustCloud, StudyBackup, and Backup Genie, 
  four other online backup services that offer identical unlimited online backup plans.

From: http://djchuang.com/2013/top-5-biggest-free-cloud-storage-web-services/

• Surdoc.com 100GB
• Shared.com 100GB [2gb max file size] Nothing to Download??
• MediaFire 50GB [200mb max file size]
• MEGA 50GB (formerly MegaUpload)
• copy.com 15GB (or 20GB with this link)
• Supersize your free cloud storage to 100GB or more (PC World, May 2013) – suggests using JoliCloud to connect multiple cloud services into a personal supercloud

From: http://thenextweb.com/asia/2013/08/30/forget-1tb-chinas-tencent-is-giving-away-10tb-worth-of-free-cloud-storage/#!stLkY

  chinese tech giants Baidu and Qihoo 360 are currently courting users with 1TB of free space
  Chinese tech company Tencent has upped the game, offering a jaw-dropping 10TB worth of free storage.

From: http://www.theverge.com/2012/4/24/2954960/google-drive-dropbox-skydrive-sugarsync-cloud-storage-competition

 Comparison chart
 

From: http://gizmodo.com/5990589/the-best-way-to-store-your-stuff-in-the-cloud

  Beefy 50 Gig
  Unlimited
  Runners Up
  

From: http://www.thetop10bestonlinebackup.com/cloud-storage

http://www.justcloud.com/why-us#ic

   8.00 / month unlimited

First reference from: First Look: BitTorrent Sync: http://blogging.cwl.cc/

From: http://blog.bittorrent.com/2013/05/23/how-i-created-my-own-personal-cloud-using-bittorrent-sync-owncloud-and-raspberry-pi/

  access our files from anywhere using OwnCloud.
  If your SD card is big enough, you can set up Sync and have your always-on Sync device.

From: http://labs.bittorrent.com/experiments/sync.html?utm_source=bittorrent&utm_medium=web&utm_content=productnav&utm_campaign=general

  Sync unlimited files between your own devices, or share a folder with friends
  and family to automatically sync anything.

From: http://www.theverge.com/2012/4/24/2954960/google-drive-dropbox-skydrive-sugarsync-cloud-storage-competition

SugarSync

If you're looking for the ability to sync and also backup multiple folders around your computer, SugarSync is head and shoulders above the rest.

From: http://pogoplug.com/

Give your employees private cloud storage to back up files from their computers, mobile phones and tablets to one secure location. Your files are stored safely in your office and continuously archived to secure offsite archival storage, powered by Amazon Glacier.

From: http://owncloud.org/sync-clients/

Store your files, folders, contacts, photo galleries, calendars and more on a server of your choosing. Access that folder from your mobile device, your desktop, or a web browser. Access your data wherever you are, when you need it.

https://www.cubby.com/

A cubby is any folder that you want to share with people or devices via Cubby. You can turn any folder into a cubby. Just drag any folder onto the Cubby application. The folder stays where it is and becomes a cubby. Leave your folders where they are and make them into cubbies so you grab your stuff on the go and share with friends, colleagues, and other computers.

http://www.aerofs.com/features

AeroFS is like a magic folder. It will automatically sync between your personal computers, and anyone you invite to share stuff with. Anything you store in your AeroFS folder is by default private. We will never store or be able to see any data stored in your private shares. This is the perfect tool for your sensitive data.

From: https://mevvo.com/

  Mevvo offers the best unlimited online backup with all of our plans. We do not limit you
  on the amount of data you can store, and will never cap your bandwidth!