It is a useful activity when there already is an organised commercial management, committed to the management of ordinary activities, but where there also is the need to start a new project and in-house resources are not immediately available. For instance, the opening of a new market, launching a new product line, establishing a retail network, market test, competitor assessment, etc.
Advantages: no need to divert the commercial management staff from the organisation of the main activities. The company project can be implemented within the established time-frame. Skilled people are immediately available, and work in parallel with the company staff, but running the project autonomously. New strategies and operational techniques are introduced, based on previous successes.
A fully-functional, documented, and repeatable vertical project will then be handed over to the customer.