The most easily identifiable reason that a service provider would choose to work with a supplier is based on financial benefits. Financial benefits to both parties and these benefits typically have a much greater weighting than any other type of business benefit that may be envisaged.
Whilst financial benefits can be generally measured over a given period of time, it is virtually impossible to set time limits on other benefit types. The one true fact is that the development of a solid relationship that can delivery the expected financial benefits and even more business benefits takes time. Time is the greatest investment that any of us can make (you can never get back the time you invest).
Time and the ability of good teams to work together for the benefit of both parties creates an environment that is conducive to good business and the flow on effect of good returns for the service providers customers.