we can't tell since no one dares to try and deposit some of their money into a random website and that is understandable.
Even if they pay out some users, it's still very likely to be a ponzi scheme. Stay away from those!
Every website nowadays displays ads on its pages to generate a certain amount of money. What if the website owner splits the ad revenue with the users? Let's say, to have a concrete scenario, that each ad viewed generates 0.20$. If initially, the user gets 50% of each ad viewed, he'll get 0.10$ per page visit
Do that without the cloud mining BS and you may actually have a viable business model.
Also to prevent people from just creating an account and leaving (which leads to only one ad being viewed), there should be a timer, for example, to click every day to start mining for 24 hours.
That's called a faucet!