What is the price of the ads?
Really depends. The latest ad of letsdice pays 0.41 BTC a month, but I'm open for higher and lower offers, as I'm nearly running into negative profit and the faucet needs more funds.
On my faucet i adapt my payouts to whatever income the website has, so it's always break-even.
Also: 0.41 BTC per month?! DANG... Why does letsdice do that? How is that profitable for them?
My site attracts a surprising amount of gamblers, it's a good demographic. And I run on donations and ads. I'm not in the negative just yet, so I have no need for reward adjusting.