Buyers can be of two types: General Buyers and Industrial Buyers.
If more buyers of the particular product belong to general category then there will be more middlemen. The reason is that the product has to reach the ultimate customer who can be anywhere in the country and to reach them, numerous middlemen are required.
In case of industrial buyers there will be fewer middlemen. The reason is the industry is the ultimate consumer and to reach them there is no need to have many intermediaries in between.