Ive been writing a guide to free bitcoins and I cant find an explanation for WHY people would run a faucet site. (I know what faucet sites do, and where to find them, just not WHY they are there)

The obvious answer would be advertising, but Id expect most advertisers would want to advertise on more professional looking sites so that doesn't really make sense to me. The pittance paid for just viewing the ads would barely cover the Satoshi they give away.. (I think) and most people getting free bitcoins wont be clicking on the links, so I'm wondering if it is about something else?

I considered it might be about building traffic to a domain name but I cant see how that's useful..finding the one domain name that might actually be valuable to someone selling taps would probably be harder than Bitcoin mining! (I think)

Philanthropic venture to share the love is another possibility but I cant believe there would be thousands of people out there feeling that generous to complete strangers (but maybe Im just a cynic)

Can anyone explain it for me? none of the answers I have found make logical sense.