customer loyalty to me is a result of a professional approach to my work.regular,reliable,trustworthy and sometimes stopping and having a little chat and a laugh.doing a good job,different payment methods,different cleaning frequencies(within reason)text night before for some customers.providing add on services.
get the basics right and you wont go far wrong.obviously some customers jump ship to a cheaper cleaner if its a well priced job but not very often.its usually more a case of "better the devil you know" than saving a few quid as so many cleaners are unreliable so they tend to stick when they find a good one.
