Why Buy a Prime Lens?

I have a Nikon D5000 and it came with the typical kit lenses:  18-55 3.5f and the 70-200mm 4f.  I love the effect that the prime lenses give in comparison to a zoom lens.  Even though the focal length is fixed, the speed of the lens is much greater and therefore allows a lot more light to come in.  When you have more light, your pictures are more sharp and, of course, more beautiful.  One of the reasons that I wanted a prime lens is because you can basically blur out the background behind your subject.  This is something caled bokeh.  I just purchased a Nikon 50mm f/1.4G AF- S from Adorama and will be posting pictures very soon to show how I used it.