consumer surplus

dinner yesterday was an amused surprise. decided to get myself long john silver's. so it's more or less the usual- combo 1: 2 pieces of chicken. but they were having some promotion so i got another piece of chicken free. that makes 3. which was nice cos i was hungry. so off i went home with my take-away. and guess what when i was quarter-way into my meal? the presence of a 4th piece of chicken was felt under a pile of fries. and yeah it left me amuthed. =0
from 2 to 4. wow talk about consumer surplus! i was definitely one contented customer.