if one site gives 1000 satoshi every hour (you have to insert captcha text) ; to earn 1 bitcoin (100,000,000 satoshi) you need 100,000 hours, approximately 4166 days (11,5 years). Who is trying to earn free bitcoin from these sites?
They are made for two reasons, one they volunteer, one obvious: 1) Show beginners how does it feels to "own" fractions of bitcoin (educative?), 2) Make money. The second is accomplished by advertising, very heavy advertising.<p>Needless is to say, it is mainly an advertising pit, and the only one making real money is the one running the "faucet."