The thing is what makes me, a consumer, want to buy from you and not Amazon? Pricing? Rewards program? Benefits of me buying from you and not them? Write these down, sort them by plain to hidden relevancy, then create ads targeted around each benefit and see if it flows. I'd also start rewording the tactical ads that Amazon uses for x keyword in your own terms. They have the advertising agencies that have the power and information to draw a sale from consumers. I'd say that you should also focus on getting repeat customer sales, but that is another story all together. I run eCommerce for a few clientele, its hard for them because they can't think outside the box with how to not play the price lower game when they can't negotiate directly with people like Microsoft like Amazon can.