Intensification of gambling behaviour may partly result from arousal caused by the mere physical presence of others in the gaming venue moving through the gaming floor on their way to enjoy other amenities. In an experiment, 56 male and 76 female participants (N = 132) gambled on laptop-simulated Electronic Gaming Machine (EGM), either alone or with a simulated crowd of 6 or 26 others who were wearing blindfolds and earphones. These crowds of other persons were falsely said to be participating in another experiment on “sensory deprivation”. Among players with pre-existing gambling problems, the results showed that these crowds contributed to a “passive/avoidant” style of gambling, whereby players generally bet smaller amounts, but were more persistent as losses mounted. These changes in persistence occurred despite the inability of these others to witness or evaluate the participants. The experiment suggests that control of foot traffic should be a consideration in gaming venue design.