This is a great idea, and here are my ideas:
• Place 4 ads on the page. The 3 that Google AdSense allows as per their policy, and 1 BTC Advertising ad where anyone can bid on the ad placement there. If your faucet becomes popular, users will create the price/bid for that ad space, which will net you some decent earnings. The highest I have ever bid towards an ad space was with Coinbooster for 0.01BTC/day, where I still only got 10% of the ad impressions after everyone else's bids for the same space. That means that all in all, that spot was producing [/b]0.1BTC PER DAY[/b], and the owner was receiving a good portion of that total from the ad network.
• Keep the faucet at 100-200sat per 10 minutes. I have 5 of the 10-min faucets open in separate tabs right now, and I never close the pages. That equals VERY GOOD quality traffic to your site and increases the average Time On Site per visitor, which will equate to higher earnings from Google AdSense. However, you can ensure that more users will stay on the page by offering my next suggesting:
• Create a minigame that takes no longer than 30 seconds as an ADDITION to your faucet. Earnings can be minimal, like 20-50 satoshi per game (maybe limit it to 1 game every 3 or 4 minutes), but this will make your overall earnings from the site around 140-300sat/10min, which will be a great contender to the other 10min faucets I currently have open (which I consider the top 10min faucets in the industry)
Keep it simple, and keep the commissions at 25% or greater, and you'll have a great formula that will provide a killer faucet where your earnings from Google will be pretty good. But the real profits will come from the network ad that users can bid for. I doubt that you'll get the 0.1BTC/day that Coinbooster (scam HYIP/Ponzi site, btw) got because of the investment nature of that site (which brought in high-rollers), but even if you earned around 0.01BTC a day from that single ad spot, that's still 0.3BTC/month, along with whatever earnings you can make from the Google ads, which will be well more than 0.3BTC/month...
Good luck, and if you design anything remotely similar to the above, your site will be added to the sites that I currently have open in separate tabs