I believe that the more users on a network the more a network may slow down, so some companies have to create ways handle larger and larger loads of users. Load balancing DEFINITION - Load balancing is dividing the amount of work that a computer has to do between two or more computers so that more work gets done in the same amount of time and, in general, all users get served faster. Load balancing can be implemented with hardware, software, or a combination of both. Typically, load balancing is the main reason for computer server clustering. On the Internet, companies whose Web sites get a great deal of traffic usually use load balancing. For load balancing Web traffic, there are several approaches. For Web serving, one approach is to route each request in turn to a different server host address in a domain name system (DNS) table, round-robin fashion. Usually, if two servers are used to balance a work load, a third server is needed to determine which server to assign the work to. Since load balancing requires multiple servers, it is usually combined with failover and backup services. In some approaches, the servers are distributed over different geographic locations. http://www.derkeiler.com/Newsgroups/microsoft.public.inetserver.iis.security/2002-10/5069.html .

Adding a computer to a network will put extra traffic on the network making its performance less overall. So the answer to your question is each time you add a computer the performance will drop slightly. On average no more then 150-250 on one signal broadcast domain is best practice for businesses.

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