Thanks for starting a conversation about marketing experiences. I have a friend who also owns his own carpet cleaning business and we talk often about how to stay busy.
I have to admit I don't do any advertising other than the lettering on my van. I have found that word of mouth has been the most instrumental in helping getting new business.
You have to really make an impression on people to get them to want and talk about you to others. When I have a slow day, I will take a little extra time to talk to the people I am cleaning for that day.
Beware the middle man. Lawyers, insurance agents, stock brokers, advertisers are all middle men. They all claim to be helping you when in fact they are just putting themselves between you and what you are trying to obtain.
To add to the avoid list I would add:
Dunn and Bradstreet (Business credit tracking)
Interlink web site builders (Canadian based, but uses U.S city phone numbers)
Most credit processing companies (I use Square)