If you want to make money with Amazon you have to do several things:
1. Use Text Ads that are SPECIFICALLY related to the INTENTIONS of your visitors
2. Products, products, products - your writing must focus on PRODUCTS
3. BENEFITS BENEFITS BENEFITS - Features do NOT Matter
1 - User intention is everything - people ignore banners and read keywords in text, Amazon lets you create your own keywords - USE THEM!
2 - Amazon sells products. If you write a long boring article about HDTV resolution your visitor might read it, but probably not. But if you write an article about a specific product - say a brand new smart phone and people find your article while looking for "reviews" of that smart phone and your Amazon Text ad says the keywords they used to find your article you might just make a sale.
3 - People don't care how many megs of ram it has, the resolution of the screen... etc. They want to know how owning the product will make their lives better. So if you are selling big screen TV's all the facts in the world mean nothing (They will read those on their own)... you have to create a mindset where owning the product is more important than not owning the product. And that means describing the BENEFITS of owning the product not some boring review listing all the specs they can get from the manufacturers site. ADD VALUE
Amazon has a 24 hours cookie so you need to ASK FOR THE SALE.
But honestly if you are doing well with Adsense then forget about Amazon and just do more of what you are doing with Adsense.
But if you do Amazon, focus on products that are unique that they can not get locally or that are at a significant price advantage. People will crack their wallet for 50 or less without thinking too much, but getting that Big Screen sale is much tougher because they do stop and think and compare... so you have to get them at the end of the shopping cycle because of Amazon's 24 hour cookie.