Mark,
That is where carpet cleaning is different to window cleaning, where people get their windows cleaned a lot more often than their carpets.
There isn't a structure for setting up regular cleans simplty because in most cases they aren't regular, but some CC'ers try and sell a yearly clean paid for on standing order.
So what you are left with is the hope that people will remember you - and for the right reasons. You can help this by staying in touch with emails etc so that when they want their carpet cleaned again, they call you.
But that will only happen if the quality and service of the job we did for them was first class. This is why it is important to set your business up from the outset with service and quality as an absolute priority, so that you begin to retain customers and build a reputation in your community from day one and not the day we wake up to the fact that skimping on service and quality in order to compete on a price level with your competitors is not going to help achieve our long term goal - a business with low overheads, high customer retention and high profits.
Simon