Sensor Shield Expansion Board v5

I have just bought one of the Sensor Shield Expansion Board v5's.

http://www.ebay.co.uk/itm/111303810093?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT.

I am beginning to wonder if I have made a mistake buying it. The blurb states that it can be used for Sensors, servos, relays, buttons, potentiometers etc. Surely the standard Uno or Mega will do the same? or am I missing the point? I can find very little info on how to use these shields. I would be obliged if someone could give me some guidance on these shields (apart from sending it back which isn't an option).

Thanks in anticipation

Brian