I tried to advertise some products from clickbank, and I got lots of clicks. But there's ZERO sales generated?

I've lost quite an amount of money for google and yahoo ads. Do you think someone stole the credits or the products sold at Clickbank are useless to targeted buyers?

Change your thinking from victim to seeker. It's a very exact science. You need to learn more to earn more. Consider a course on cpc marketing. Arbitrage the cost of your ads vs the cost of acquiring a sale. Set your daily budget at $25, but bid high per click. Bid on lower volume key word phrases to begin with. Avoid single competitive key words. 50% of searches are misspelled key words and are less expensive to bid.

You can do it. Be encouraged.

Then i must say you should change your strategy.