Calculation based on 1THS at today's BTC/USD price.
Today's difficulty: 35,985,640,265
Seconds per day: 86400
BTC/USD: $354.52
AMHASH1: Income: 0.013975~ Fee: 0.004606~ Net: 0.009369~
Competitor: Income: 0.015676~ Fee: 0.008969~ Net: 0.006707~
Change: 0.002662~ (39.7% increase)
Don't know about competitor but AMHASH1 calculations are correct.
And now a little entertainment for brain. How much BTC need to cost to get zero divs? At current diff of course.