You can check out the BNI (Business Networking Inc.) group in your area by going to their web site. BNI is a world-wide business networking group that works by referral only. I belong to the Circle of Success Chapter in Wisconsin and I have seen two cleaning companies go from the beginning stages of entrepreneurship to leaving the group due to the fact that they had more work than they could handle.
There is only one profession per group, therefore, anyone needing cleaning services will refer that business to you.
A word of caution, however........you must provide two references on your application and they also do a background check. You also, must perform well. It is a very strictly run referral organization and the members take those referrals very seriously.
You can locate me at http://www.bniwis.com. Enter site as a visitor and click on the "forming chapters" tab or check on the established groups in your area and click on the tab that gets you to them. From there you can see if there are any existing chapters that are currently seeking the cleaning profession.
It is not always easy to get into a group. Sometimes you have to go on a waiting list, but once you're in, it is well worth it.
If you do a great job, you will grow leaps and bounds.
Hope this helps.