If a buyer pulls up to your house and sees that you have made a big home improvement for them already, they may be more apt to purchase your home than one where they would have to incur the expense of having them done.
Everyone who lives in earth have desire for beautiful and stylish residence. One thing which amazes first time carpet cleaner users is the sheer amount of dirty water pulled back out of the carpet - once you've used one you'll never go back to non-carpet cleaner days again.