Thank you for the $6.00 you gave me for participating in one of your psychology experiments. I'm assuming you paid for it, because it costs so much extra to take business classes here, and there's no way our Psych department could afford to pay everyone this much cash. Plus, everyone else was there for extra credit in their economics classes.
Anyway, I'm sure you'll be glad to know that I will be spending that six bucks on three $1.99 margaritas tonight. We really had a mutually benefiting interaction today, Econ Dept: I contributed to your research, and you contributed to our campus's excessive drinking. Everyone wins!