The service will offer 50GB of storage for free and three Pro tiers of 500GB to 4TB for $13-$40 a month.
How it is different?
The difference that makes a difference is that all files are encrypted using a 2048-bit RSA key. What this means effectively is that Dotcom cannot be accused of knowingly storing copyrighted materials because he cannot technically know the content of the files stored on MEGA—only the user who uploaded the files and/or possesses the key can.
For a full review about Mega please refer to this article.