Retailers are the intermediaries who sell to end consumers, while wholesalers sell to businesses (and typically deal in larger volumes). (Ingram is...

Retailers are the intermediaries who sell to end consumers, while wholesalers sell to businesses (and typically deal in larger volumes). (Ingram is the largest one in the U.S.), who then sold the books to retailers, who in turn sold to customers. There is a widespread belief that intermediaries take profits without adding value (since they do not physically alter the product). So why are there intermediaries? What good are they?