Our Digital Network limits the number of Agents from a Country, why?

Usually, different Freight Forwarder Networks offer membership to any Freight Forwarders around the world up to any numbers per country. This obviously looks like a chance for all Freight Forwarders to be a member in a reputed group such that all of them feel a big opportunity to grab maximum business from the group. But, in the actual sense, the profit margin through this pattern is not so easy. Because, the more a network allows membership from a certain area, the fewer chances to get business from there, due to an ultimate range of competition!