The single biggest problem causing application performance are wild users. When a company fails to teach users about the intended uses of the network, users assume that it's there for their entertainment. Downloads. Streaming. Chatting. It's the same as if you put a sign out in front of your house "Free room and board--ALL WELCOME!" Before you'd know it the place would be swarming with people and it would be wrecked. Application performance is a function of sound network management. Unfortunately, today everyone equates good management with buying more and more automated gear. It does nothing to improve performance, but does earn the technologist who bought it a "shiny merit badge" they can use to ask for more money as they move from company to company repeating the same poor decision making.