My opinion, this sort of advertising attracts the wrong sort of customers.
you will get more calls yes.
but you will also end up cleaning dirtier carpets, have more cancellations, have picky customers who expect the earth and are never happy and not get repeat business because there will allways be someone cheaper.
Also you end up with all those really awkward jobs were you get really trashed carpets, and there wafer thin foam backs that you know are gonna shrink or ripple if you go heavy handed on them and you also know if you dont there not gonna look any better :

wouldnt you rather clean nice quality carpets with low soiling in nice quality homes for people who apreciate what you do and are willing to pay you a reasonable price for your hard work, and are happy to come back to you time and time again?