Assume marketpower ~ profit, consumers are rational blah blah blah
Firm A = $100m profit @ time t, assume 100% of market power
@ t+1 Firm B takes 50% market share, profit = 50% each
@ t+2 Firm C takes 33% market share, profit = 33% each
@ t+inf Firm .......... 0% market share, profit = 0% each...