ive searched this topic but cant quite find out how exactly these things function. im not quite sure how a midi switcher such as a Ground Control can switch on and off individual pedals and stompboxes in racks, how does all of that work? what is the purpose of MIDI in this process? how do players control stompboxes with a switcher? how is something like this wired? i clearly dont know much so some help and explaination would be much appreciated. thanks! 
It can get very expensive. But you can get 8 loop switchers for under $400 new, and if you only need a simple controller like a MIDIBuddy, you can have a setup for around $500.