Three Main Successes with Cloud Computing
Portability
Where there's internet, there is access. Instead of having access to programs and files on only one computer, Cloud-based services can be used anywhere from any machine as long as it can connect to the internet. An example is how Microsoft Word can only be used on a computer if it is installed, but the Cloud-based Google Docs is more flexible. In general, this makes the Cloud much more portable than hard drives, especially when dealing with a lot of data.
Lack of Hardware Requirements
Possibly the largest plus of the Cloud is that it has very few requirements. Since computing is done outside the local computer, you don't need a top-of-the line machine with a blazing fast processor to take advantage of Cloud services. A simple browser on an old computer would probably be enough to create a Google Doc on.