Even a child needs an extra income to buy things they want, like games, toys... I don't see problem on it, everyone in this world needs money, since baby until an old one.
Faucet are nice, or anything more like a game, that's a good alternative for their videogames in their PSP's or in computer, atleast by that they are earning, but I am afraid that kids at young age should not be stressing themselves thinking about money. We never know what they will think if they are not earning well in those faucets or games, who knows, they might end up starting to ask money from their parents and keeps on doing that for no reason other than just to have money. - which is always the start of a child's idea that they should always have a lot of money.