Now that I have answered the original question personally, I'll propose a more generalised version.
Here's a marketing method that you can't buy, but costs nothing, it's self perpetuating and requires no input from you.
Repeats and Recommendations.
It is easy to see the job as the be all and end all, but actually it is only part of it. What a lot of people don't realise is that WE, our business as an entity and ourselves the service provider, are in our own right a marketing machine. If we provide people with a first class service (first class being a journey and never a destination) that starts with the first contact and ends when saying goodbye at the end of the job, then your customer's will be more than happy to share their experience with you on Facebook, tell their family and friends and offer your name up whenever the subject of carpet cleaning comes up at work - in other words, they become a marketing wing of your business and all without you having to do anything or spend a single dime.
So if you want this wonderful form of free marketing in your business, work really hard on every aspect of your service and your diary will become more and more populated by repeats and recommendations and your advertising budget will keep going down and profits will go up.
Simon