Speedy Mirror is a distributed cluster for your content delivery. It is a system of computers containing copies of your data, placed at various geographical locations so as to maximize download speed and availability of the data.
You will receive 50GB of free bandwidth to consume after that you have need to pay them to use CDN . If you want to know how to integrate this with WordPress Please post here I'll try to help you. Thanks
http://www.speedymirror.com/ ( Not an affiliate link )
I'm not associated with this speedymirror.com, found it useful so I thought good to share with my friends here.