Crypto currency is now very interesting to many people and so I think that this will be interesting to many. But you need to attract many advertisers to your site. And clients
You don't really need to attract advertisers, you can just pick and choose whatever advertisings you want, unless you want to make specific deals for your faucet.
I'm guessing that some advertising networks aren't compatible with faucets, because they're against their TOS, but you'll still have many to choose from.
Faucet was booming awhile ago, when Google Adsense looked the other way, but these days, they have been read the riot act and fauceting is seen as incentivized traffic. For same reason, the network sites that tolerate faucets, pay very little thus making faucet owners hardly able to offer rewards that could engage people and not see it as waste of time.
To generate extra revenue, you may want to consider promoting your own affiliate links from programs with potentials, the very popular ones are likely to be saturated already.