Gambling can never be considered as a investment, because with investment you have assured pay back after certain time period but with gambling nothing is assured. So in my view gambling can be considered a earning source and not as a pure investment.
You can never be sure that you will get back what you have invested...
In this case, gambling is much more transparent. You instantly see if you won or lost.
Well I will not agree with you. I invested in a gambling casino site and I got it back plus the interest. I don't think gambling can make your money back since you can lose if you are not lucky. Rather than passively wait for your profit in investing in a legit bitcoin casino gambling site. Well if you are looking for legit casino site. You can message me and I will tell what bitcoin casino site I am investing.