Yes. If you use the right methods, then you may be able to earn a lot more in (advertisement) revenues when compared to the expenses. Keep in mind that you need to set a slightly harder threshold. If your faucet is giving 0.001 mBTC at a time, then make the threshold 0.1 mBTC. The user needs to visit the site 100 times, before he can withdraw the payment. Only a very few are going to have that much patience.