I cleaned carpets in a former life. (What a racket that was!)

If you choose to clean them yourself, make sure to completely rinse them of whatever cleaning agent you use. If you don't, even though they'll look great at first, the soap/cleaner will dry with the carpets and then act like glue to attract new dirt.

I don't know how many people's carpets I cleaned that had cleaned them themselves and left a lot of soap in. The dirt would come right out, along with a lot of suds that would clog up my machine!