Dare I ask why,although I'm guessing the answer will be "because I can"
There is actually a perfectly legitimate (but long) explanation, but you can have the short version
A) Firstly the router is located in my living room, there are two data points located next to the hub, two next to the TV, two in one bedroom and two in another bedroom. I have network devices in each of these locations (TV, DB, ATV etc)
B) All the data points terminate back to my office where the switch is located
C) In my office I have my server, NAS, two desktop PC's and two printers The NAS is connected to the switch using an LACP trunk to aggregate data (something you can't do on a noddy switch). One of the PC's is my primary point of use, therfore this is my focus in terms of speed of internet access (as well as the servers/NAS as the storage is presented over accelerated iSCSI)
D) One desktop PC is connected via a pair of homeplugs, one of which is connected to the switch (this is clear in point F) the other desktop PC is connected directly to the switch (as cited above)
E) The server is connected to the switch using a teamed pair, with the ports on the switch also set as a trunk.
F) The TV and ATV which resides in my daughters room is connected to a small hub (she doesn't require much bandwidth) which in turn is connected to my core network (back to the main switch). As she also uses a laptop/iPad/iPod etc and it's in my extension where wireless is pretty much non existent she has a wireless homeplug (again this connects back to the switch in my office)
G) As there is no data point in my conservatory (lack of forsight on my part), this also has a homeplug which again routes back to the core switch.
Now consider my switch is 48 port and the router has only 4 ports.