1. Create an Amazon affilates link to the product you want to arbitrage. The guy advertising this laptop used this affiliate info: tag=track25-20&linkCode=ur2&camp=1789&creative=9325
2. Based on the price of the product your advertising, determine how much you’re willing to spend in Google Adwords and setup a campaign using the affiliates link you created above. Be sure to put “amazon.com” in the text of your ad, because this is a trusted vendor and it will help you get clicks.
3. Once you started getting clicks, examine your conversion rate and tweak your ad bids until you’re profitable. For example, suppose your conversion rate is 2%, ie, 2 out of every 100 people clicking your ad actually buy the laptop. Your ad spend should be .02 (conversion rate) * .04 (referral fee) * 1549.00 (avg. product purchase price) = $1.2392. As long as you spend less than $1.24 / click, you’re making money.
via How to arbitrage ads with Amazon Affiliates and Google Adwords