I bet OP doesnt even have 1btc.
He is only saying he will give 1 btc to a "random" person, so that loads of people advertise his site.
OP, could you sign a statement using an address containing at least 1 btc to prove you have enough to pay out at the end of the month?
How will the random number be chosen? How will you correlate the number chosen to a person? Will you give numbers out to people before the random number generation?