Personally i think this is a great Subscription to have and may save you one day if you accidentally delete the contents of your phone or if your phone gets stolen
Its $2 per device, consider it a cheap insurance policy if you value your phone contacts, phone messages, photo's etc.
Basically it lasts for the lifetime of your phone (Android, iOS and Windows Phone) so for most people that would be 2 - 3 years. And you can only use it for 5 devices, once you register a device you loose that slot and have 4 more etc . Best of all you can directly transfer all your data to your new phone (Android <-> iOS). Or share the 5 device subscription with your family and friends.
Also available @ Gizmag
Enjoy
Does it support iphone cloud backup and restores tho, if it doesnt, its not worth it