it is like a gamble but not in its ultimate sense just something like that, being in a bounty campaign doesn't really guarantee you a money. but sometime if its real you can earn some profit which is happen so often. Like in the Forest Gump Movie Quotes. Life is like a box of chocolate you never know what you going to get.
Indeed, participation in the generosity programs ICO is somewhat like a gambling game where you can successfully win or lose completely, depending on the success of the chosen project, since it is quite difficult to predict which of them will be successful and which is not.
In general, this is quite a fascinating and quite profitable occupation. Especially for low-income countries, this is a significant addition to the main work. I would not advise you to go completely to the campaigns of generosity, because profit is not regular and we do not know how long such programs of generosity will still exist.