Project managers have a name for giving a customer more than the plan calls for. They call it gold plating. Wikipedia sums up the standard project management guide, the PMBOK, this way: gold plating “means the addition of any feature not considered in the original scope plan.”
In 2002 PM Network, the magazine of the Project Management Institute, discussed the practice. It wrote that giving the customer extras, such as bonus functions or better components, “usually is frowned upon in project management circles.” It quoted an exam guide by Rita Mulcahy: “Often such additions are included based on the project team’s impression of what the customer would like.”
The same article questioned the rule. Its subtitle reads: “A certain amount of ‘gold-plating’ in software development projects actually may produce more satisfied customers.”