Great article. I learned through experience to do exactly what you suggested - don't panic, think about what you can do to improve your business, and most importantly MOVE ON. Every time I've lost a big client, the following year has seen IMPROVED business! It helps keep us hungry, and make changes to provide better service. I've usually found, looking back, that clients that move on were the difficult ones - wanted discounts on their bills, didn't appreciate my efforts, and took up a disproportionate amount of my time. Once they were gone, I had more time to commit to my other clients and to grow the business. It makes for a few reduced cash flow months, but it can actually be good for your business long term.