Starbucks has been very successfully selling high-priced coffee despite the fact that consumers could easily substitute Starbucks coffee for less expensive coffee or substitute its coffee for less expensive drinks like soda, bottled water, or fitness drinks. Why do you think Starbucks has historically been so successful avoiding substitutes? Do you think its advantage is eroding in this area? If so why? If its advantage is eroding, what could the firm do to change this situation?