Seatmate Lotto is the chance you take whenever you take any sort of public transportation or an airplane. On a bus or train, the lotto is simple- you already have a seat and, as you scrutinize the passengers that pile on at a given stop, proceed to cross your fingers and hope the alcoholic hobo doesn't decide you look like a friendly enough sort and nuzzle up to your shoulder. More often than not, actively participating in seatmate lotto will guarantee this outcome as the hobo will see you watching him and decide to spite you in an instance of karmic justice.
On a plane, seatmate lotto is given considerably more importance. Because you see everyone who might be your seatmate while entering through the gate, you try and pick the hot young girls and avoid the fat mid-western women at all costs. Since none of them can sit with you out of spite karma doesn't come into play and the process becomes a slightly more enjoyable, if meaningless, gambling experience that can determine just how much you enjoy your trip.