Well-functioning marketing systems necessitate a strong private sector backed up by appropriate policy and legislative frameworks and effective government support services.
Such servicer can include provision of market infrastructure, supply of market information (as done by USDA, for example), and agricultural extension services able to advise farmers on marketing.
Training in marketing at all levels is also needed.
One of many problems faced in agriculturl marketing in developing countries is the latent hostility to the private sector and the lack of understanding of the role of the intermediary.
For this reason "middleman" has become very much a pejorative word.