Investment is buying some shares of an asset and hold them till they appreciate in value for more profits in the future, too far away from the meaning of gambling, they are not the same.
Therein lies the answer, gambling is not an investment, gambling will always be an expense, something that we should not romanticize as an investment, the word itself is one, gambling is basically an expense, a risk where there will be no ROI, unless there is very good luck, and that does not always mean winning more than what was bet.