Sometimes you can write a great ad promoting a website, and often times people won't buy anything. You're left paying google your fees and you haven't made a sale. Please, help me.
WOHA! Careful there… you're threading on a fine line. And the product that was recommended above: STAY AWAY!
There's no such thing as free AdWords. What that product suggests (and that's how people say they get AdWords free) is something called AdSense arbitrage. Read up on it:
Google is really cracking down on arbitrage though!