During the 1980’s there was a general consensus in the market place that you shouldn’t clean your carpeting too often, it would take out the stain protection from the carpeting. Many people still believe that this is true. I will argue that this is the wrong approach to carpet maintenance. Once you start seeing that the carpet is getting dirty, you have already started harming your carpeting.
Carpeting is mostly made out of nylon fibers. These fibers will get damaged when the carpet gets dirty. If you were to look at the fibers under a microscope, you would see this damage occurring. It is similar to what happens when you run sand paper over Plexiglas. You are sure to see scratches in the Plexiglas and will not be able to remove them.