Some customers are very demanding. They sometimes threaten to stop implementing the product or stop paying the Support and Maintenance contract. Although, from your Support and Maintenance Policy, their reported Support Issues should be closed, you could loose these customers.
A large or well-known company using your product is good advertisement to convince other candidates to buy your product. Doing a bit extra keeps the customer happy and will probably spread the news. More income could come out if it. What are you going to do?A customer not paying his Support and Maintenance contract (sometimes for good reasons) is very bad advertisement. This customer could ruin your reputation. What are you going to do?