well i believe that there is an adavantage in segmenting your LAN. firt of all this would secure your network. if you have data that is only used within your local network then you could put it into one of the segmented networks within your organization setting it aside from the Internet which is very prone to security treats. on the otehr hand you could make another segment as a network for Internet access only. this wil greatly improve network security within your organization most specifically if internet usage is not much of a priority.
aside from security, you could also easliy manage your network most specially if your dealing with a large netwrok. this would not be a burden for you knowing that you have "grouped" your network accordingly. so that if one part of the network fails you could easily determine which segment it belongs to.
