Round Reciprocation

I went out with a couple buddies this weekend and did an analysis of Round Reciprocation. By Round Reciprocation, I mean the idea that when I buy a round of beers for four of my buddies I expect a beer in return from each of those guys. I bought the first round so as to have enough time for all my beers to be reciprocated. Of the four dudes I bought beers for only two reciprocated. The annoying part is that later in the night these non-reciprocators went up to the bar and bought one beer for themselves disregarding the code of reciprocation and forcing me to buy my own. I did some math and realized that if I go out and intend to have four beers one night with this crew I am actually paying for three beers to drink two. A pay to drink ratio of 3:2 is no good. Something else to be aware of is the guy that drinks premium beer when you are buying a round but switches to domestic when he is buying the round. People need to be cognizant of stiffs like this because although it seems petty these things add of up over the length of a bar career.