I would give a zero if that was an option. The technician showed and looked for 20 seconds up our main vent. We just wanted a basic clean of our vents, he said we needed sanitizing and a number of other things done too, our course all of which will cost extra. My wife told him not to worry and just complete the duct cleaning we paid for. He flat out refused and said he needed to perform a full service. Looks like Mr Duct uses the Groupon to get into your house so they can scare you into paying for extra services. I filed a complaint with Groupon, beware of using this company if you are using the Groupon. Shady bait and switch tactics from the other reviews it looks like this is their standard practice.