"Toller" writes:

After the answers JohnB got below, I am almost afraid to ask!

Our berber carpet is 5 years old and is getting a bit dirty in high traffic
areas.
My wife says we have to get it cleaned or it will damage the carpet.
Is that true? I would think cleaning is harder on it than being dirty; but
don't really know.

Do commercial cleaners use various methods? Any better than others?

Home cleaner is great.

The number one thing that wears out a carpet is the dirt in the carpet.
The dirt gets into the fibers and then you walk on it.
It's like sandpapering the carpet.