I'm related to this kind of game. When I'm with my friends and we are on the road and nothing to do. We are betting on the color of the cars but we have some special rules to set. Like we are setting a certain period of time then we choose a color. The most car with our chosen color that passed in that period of time will be the winner. The loser(the lowest number of car color that pass through) will treat everyone.
Or big losses. From your statement, you are treating gambling as a source of profits/income. Which should never be the case. If you were gambling on such petty things like simple trading cards, cars passing, or whatever small bets, it is still gambling. It may not be the usual thing like dice and slots but it makes something like this a lot more interesting as you wage on the outcome of something.
and if he use gambling as a source of income, then I don't think that he can earn much money. I think if we were gambling like that, we don't have to case the profit but its more have fun with our friends and I think we can enjoy the time while we ride on the way. sometimes I do this too with my friends but the bets are who is the winner will get a gift for some free dinner from the loser.