Carpet Cleaning
The first reason is because of the appearance. Clean floors make everything look better. When you have company over do you want them to look at a dirty and stained floor or a clean rug? Of course you want a clean floor. A clean floor shows people that you care about your home and take pride in its appearance.
The next reason is that a clean carpet just lasts longer. Dirt is abrasive and will ruin your carpeting if left in place. Every step you take on the soil in your carpet grinds it into the fibers. This permanently damages the carpet and will cause it to wear out much quicker. Compare the price of carpet replacement and the price of regular cleanings and you will see the benefit in cleaning your carpet.
The last reason is for your health. Clean carpet is just healthier. Do you want your kids crawling around on dirty carpets? Of course not. Do you have allergies? Carpet is like a giant air filter for your home. It traps dust and dirt and keeps it out of the air that we breath. This filter does need to be cleaned from time to time. Once it is full of soil it stops improving your air quality and starts hurting it.