I am also baffled about the use of the terms investment here too. Is it the money use for gambling or money used to invest in a gambling platform which in return will give a person some passive profit in depending on the platform profit?
I don't understand why you guys are getting so confused here. Investing itself means pouring your funds into something with the expectation of acquiring profit which is what gamblers try to do with their funds in gambling sites.
Gambling is wagering/staking something with an uncertain outcome. While on the other hand, investing can be said as committing to something with a calculated expected outcome, consequently owning parts of the thing you are investing.
If the gamblers only play on the site, they own nothing. It is inapplicable to investors since they own part of the shares/things, regardless of the outcome. So I believe both things should be differentiated.