I'm surprised the legitimate ones still exist.
Say there are 10 such sites each which allow 1 freebie per 24 hour period.
Let's say an enterprising individual has a way to secure 10,000 IP addresses per day and each one pays on average 0.0001 BTC
Then:
10,000 * 10 * .0001 = 10 BTC
= $1050 USD / day (at $105 USD = 1 BTC)
It's good to see people haven't ruined it for others by now if free bitcoins are truly still being given out.