Never tried groupon but i find this thread interesting, the way i see it is that you are paying groupon to do your marketing, you sit at home and they get you 100-300 and you go out and do the jobs and try to upsell wherever you can.
You have spent no money on advertising/marketing
You have spent no time walking the streets
You have guaranteed work
Work out how much you could/would spend on advertising/marketing to get that money guaranteed and you have the answer to the question........is it worth doing groupon?
Wether it devalues carpet cleaning as an industry, i doubt it as so much of the population dont or ever get their carpets cleaned.
I dont doubt that it has worked for the people on here who have admitted to doing it and some people on here just protest far too much for them to be credible.
That said i still cant decide wether i would do it, but, if your going to thrive you have to be open to new ways of marketing.
Tony