You are in a crunch and need access to PowerPoint but the IT staff has not loaded it onto your computer. The presentation is due tomorrow and you still need to fill out a prerequisite for additional software. It will be at least a week before the software arrives for the IT staff to set up.
Forget all that! With the cloud all you have to do is ask and in minutes you will have access to the applications you need. No waiting and no installation. If you only need the software for a month, it can be removed just as easily. You are in control of what you need when you need it. No need for an already burdened IT guy to show up and consume your time.