A critical concept that service providers must internalize and act on is "making your products and services more worthwhile in the eyes of the customer". Sometimes service and sales organizations actually will continue to improve on the product and service they're offering and regular basis, but are lax in making sure the client understands the increased value they're receiving. That's potentially just as dangerous as not providing the added value at all. If the client doesn't recognize the value, it won't be appreciated. The added value will do nothing to improve your standing with the client or separate you from the pack. Periodic meetings with the client sponsor, when possible, who actually signs the check, in which you walk them through metrics that speak to the client's own KPIs, can be a lifesaver.
This is part of a much larger topic that is relevant across the entire lifecycle of business investment in goods and services. Program and project portfolio ROI analysis, selection and prioritization of new investments and projects, ongoing monitoring of project and program delivery, and post implementation assessment all share the same need for well defined measures of value that are meaningful to each of the stakeholders and speak to the needs that drive their decisions. Routine communication between provider and customer, with an agreed upon way of monitoring and reporting on the value provided, is a key component of a positive, long-term relationship.