My ideal Carpet Cleaners:
Set an appointment time and show up at that time.
Would wear clean uniforms and paper shoe covers, like doctors in an operating room.
DO NOT show up with a machine that looks like the old-fashioned "Rug Doctor" machines that are rented at grocery stores - - and hook it up to my sink - - and use up all my hot water - - and then leave the carpet a soggy, wet mess that takes days to dry, while growing MOLD underneath in the foam carpet pad. (Yes, this happened, and I've never called that company again!)
Use STEAM to clean.
Use all-organic soap with break-down enzymes on stained areas only.
DO NOT use chemical soaps and dirt-repellers (Scotch-Guard). Did you know that DuPont uses a chemical that is a proven carcinogen? - - yet our government gave them a couple of years to pull it out of all their products! My kids are walking barefoot across this carpet - - I don't want one of my children to have leukemia when they are 25.