Every time we get one of those coupon books, there's an offer for air duct cleaning service. Being the OCD guy that I am (and knowing that it was highly unlikely that the previous owners had done it), I figured...what the heck?
$260 later, my ducts are cleaned. Hard to say if anything really changed for the better, but their machines sure made a lot of noise...which gave me the impression that they were really doing something. I checked the vents afterwards and, yes, they were cleaner (I had noticed some of the dust before). The two 23 year old guys (from Siberia!) had opened up my main duct and then screwed a cover on it.
They also showed me how much dirt hit my filter (needed evidence, I suppose).
What this taught me is that perception is better than reality. I have NO idea what they really DID. All I know is how it made me FEEL.
I felt like I was doing something for my family. I felt like the air was cleaner and more pure. I felt like I had made a decision.
For all I know, nothing's changed except for how I feel.
This is a great lesson in marketing...it's how your customers (be they paying, investors, students, congregants, whatever) FEEL after the experience as opposed to what actually happened.