I've talked about apologies before, most recently with respect to the JetBlue troubles in the aftermath of the storm that hit the northeast on Valentine's Day (see my posts, What Can Lawyers Learn from JetBlue's Recent Troubles?, Is It Time to Issue an Apology and More on Apologies). Michelle Golden of Golden Practices also frequently discusses the importance of apologies in business. She recently summarized a Seth Godin post about effective apologies. Her post (and Godin's post, here) focuses on taking full responsibility for the problem.
If you think all of this talk about apologies doesn't apply to you, consider that your best source of business is always your existing clients. No one is immune from making mistakes. When you make a mistake, apologizing appropriately and doing what you can to rectify the problem is good business. It may save (or even improve) your relationship with that client and your reputation.