Now, I took the liberty of deploying a nice CRM system which will keep track of your costumers, along with how much the owe you. So you'll be able to know the good customers, the customers you might want to make an offer they cannot refuse, the customers you need to cut out the thumbs, the customers in need for a good Kiss of Death, and those customers we might need to wack and bury in the desert. As every muder-associated company (such as the mafia and the hitmen) knows, it is more expensive to bring new customers into the company than wacking those who don't pay in time...
You'll be able to access all those information in a easy user-friendly web-oriented interface!