Bitcasa is what Mega wants to be
I have followed Bitcasa ever since it started to offer its service as a beta version. It is a cloud hosting and synchronization service that does a lot of things right. First and foremost, it offers client side encryption of data, something that the recently launched Mega is offering as well. All files you uploaded to the service are encrypted locally with AES-256 so that they are stored in encrypted and thus protected form on the Bitcasa server.
Bitcasa, unlike Mega, is offering its users a complete package that consists of a website compatible with all recent web browsers and clients for various operating systems to access data on those systems and synchronize files between them. Clients are available for Windows and Mac systems, as well as iOS, Android and Windows Phone. A Linux alpha client seems to be available as well.
All folders on a desktop computer can be synced with Bitcasa which means that it is not limited to a root folder for that. On Windows, users can simply right-click a folder and select to copy it to Bitcasa or mirror it instead. Copying simply copies the current files and folders to the online storage, while mirroring will keep an eye on the folder to sync any changes made to it to the cloud.
Bitcasa recently came out of beta introducing two plans to users of the service. All users who sign up for Bitcasa can join the free plan which provides them with 10 Gigabyte of online storage space. While that is less than Mega's 50 Gigabyte of storage for free accounts, it is still more than comparable services such as Dropbox, SkyDrive or Google Drive are offering to free users of their service.
What may make Bitcasa interesting to some though is the only paid plan the company is offering. For $99 a year (currently discounted at $69, also available for $10 per month) users get unlimited storage. The infinite plan on top of that offers an unlimited number of file version changes to be stored on the servers, and chat & email support.
I'm always wary when it comes to companies that claim to offer unlimited storage as there is no such thing (even if you would stack all available storage devices of this world, you would not have unlimited storage space). Being wary does not mean that you should not consider the offer, only that you should keep a local backup of files that you push to the cloud for emergency recovery.
When you compare Bitcasa to Mega, you notice how advanced the former is in comparison to Mega. While you do not get as much storage space if you select the free account, you do get client side encryption just like you get when you use Mega. On top of that, you get clients for various operating systems, an online viewer for various file types and documents, and file versions support.
Update: Bitcasa announced today that it will shut down Bitcasa Drive on May 20, 2016.
Customers of the service have until May 20 to download their stored data from the service before it is deleted permanently.
On May 20, 2016, the Bitcasa Drive service will be discontinued. You will need to take action to avoid losing your stored data.
You will have until 11:59pm PST on May 20, 2016 to download your stored data.
You will continue to have access your account until 11:59pm PST on May 20, 2016, after which all accounts and stored data on Bitcasa Drive will be permanently deleted.