I mean - how many flights were you on 3? 4? Statistically that doesn't even move the needle to be conclusive. Perhaps you were just on a route that has a high amount of wealth on either end (IAD, DCA, SFO, LAX, all NYC airports).
FWIW, when I was a college student I took the bait a couple times when factoring in the cost of my checked bag it was basically a wash.