It is a direct debit facility. It enables your company to put your customers on a direct debit option the same as your telcos and utility companies. The difference is you only take the payment when you have done the job so the benefit for the customer is if you are late one month the payment doesnt automatically come out without the windows being cleaned. If you use Cleaner Planner not only does the customer pay you as soon as the job is done but it is automatically registered as paid in your database. 
You don't have to do it like that though.
All my GC customers pay on the first if the month. Even if their clean isn't done until the 31st.
I love it.
Just 'cause you wouldn't be happy with a method if payment, doesn't mean your customers wouldn't.
I'm now up to 118 customers paying GC.
For some people, it's great!