Most of us that have businesses of one sort or other have had a disgruntled client at one time or the other. That is going to happen no matter what as that is the nature of people sometimes. That is a part of all businesses. One thing I try to do to eliminate any issues is to be overly specific when explaining my service to clients. I am actually so anal I get funny looks (well, funny emails) from prospects because it can come across that I am taking down to them. That is far from the actual truth though. I have found that people do not hear everything you say when you are talking with them and it is your responsibility, as the business owner/salesperson/customer service representative, to make sure that the client understands all that could possibly be involved with what you are selling. If not, the fault lies with you as you did a poor job as a vendor/supplier. I once wrote a man a check for 1,000.00 as he bought a site from me and did not follow my instructions as to how to rank it even though I supplied an eBook as well as told him at least once via email to read and follow the eBook. What I did not do was to make sure that he understood the process 100%. I figured I give the guy the book, tell him to read it and follow it and he would be good. I failed as a service provider when I did that. It is not unlike a car dealership selling you a car and saying "read the service manual" yet not reminding you that you need to change the oil in the car and the motor blows. Sure, the buyer should have read the manual, should have changed the oil, should have taken care of the car but did not. Sure the manual says every X,XXX miles change the oil but the buyer was a driver of the car and not a mechanic so he just drove it until he heard noises from hell under the hood. If the dealer called him and reminded him, sent him postcards and letters... reminded him that maintenance was important then maybe the car would still be fine. Be the guy that reminds your clients that they need to follow your instructions after the sale. Be careful to remind them in ways that will motivate them to do the proper thing when they are your client and don't just do it for the upsell. Do it because you are a responsible business person and you want the best for your client even if what they are going to spend their money on after the fact is not going to line your pockets with gold. The responsibility to see your products and services provide the best value to your clients is on you and not on the buyer. You need to be proactive and share with them what they need to do and then FOLLOW UP on what you told them. Following up ensures that you will have a happier client and one that gets full value out of what you are providing + it will give both them and you a peace of mind that comes from providing quality customer service.