As noted here I had my heating system repaired Monday. I got the bill today considerably faster than my previous experience with this business. So I am tempted to speculate about the reason. Is business slow leading to no backlog of invoices to prepare and mail? Or is business slow requiring more attention to be paid to cash flow? And if business is slow is this because of the economy or because of seasonal factors? Or maybe they just have a more organized person doing the billing. I guess one data point doesn't really prove much.