Caller ID says "MASSACHUSETTS". They leave a message. I do not call them back.
Their software is too stupid to wait for the beep, so the beginning is cut off. I searched elsewhere on this site and based on the snippets I have, I reconstructed the whole message. Their message is "To improve your indoor air quality, we are offering air duct cleaning service for $59.95 <end reconstruction> for unlimited vents to a single furnace. We will also include a free dryer vent cleaning to prevent fire hazard and a free furnace inspection. To hear more about this offer, please, press 1, or press 2 to be removed." There are other versions where the cost is $39.95. I searched this site for the phrase "for unlimited vents to a single furnace". This brought up about 5 numbers with 317 608-1525 having the best write up.
Like most of you, I am on the federal do-not-call list. So they are ignoring the law.
A few years ago our furnace died resulting in our ducts being filled with soot. I looked up reputable duct cleaners with the popular home maintenance review site A****'s List. If I recall correctly it took 3 guys and about 2 hours to do it properly (they needed to access everything in the basement and at each vent. I think it cost about $250 (considering they only recommend doing this every 5 years or so, the per year cost is cheap). I can't imagine that there is any way they can do a half way decent job and make a profit for $60.
I believe a lot of these companies come in and make a big show, but really very little cleaning is done (I think a Canadian TV channel investigated air duct cleaning - the videos are on youtube). Since you can't see in the ducts, you have no idea how well they have done their job (hint: very poorly).
As to the phone calls, the exact same phrasing has been around for at least 4 years, and all around the country. I suspect that one company (possibly overseas) does the calling. When someone says "yes", they pass this along to a local (and likely sleazy) duct guy.
Don't bite! If you need this service, pay more and get the job done right. Do not support their sleazy phone tactics and poor quality work.