Of course the guy's sales increased when he eliminated all outside links. He stopped inviting visitors to leave his site. I've seen several ecommerce sites that also ran AdSense and other affiliate ads. This is insane if you want to keep visitors focused on your products. Due to the nature of contextual advertising, the only links likely to appear are those for competing products.
Be aware that if you are using the Amazon aStores code, you do not have any content on the pages. The content is provided through iframes, which are not part of your site and does not appear in the code for your pages. Spiders ignore iframes content. You have to add content to the pages if you want something for the spiders to focus on.
Don't use reviews and product descriptions from the Amazon site. That's the kiss of death for an Amazon affiliate site. When the Panda updates started, a couple of my automated Amazon stores were de-indexed. The sites were not using aStores code, but were using content pulled directly from Amazon through their REST datafeeds. The content for half of the sites was automatically spun and the sentences re-arranged before it was displayed, but Google still caught it. All 6 of my Amazon datafeed sites crashed shortly after Panda started. My monthly Amazon revenues went from $2,000 to $3,000 to less than the price of a pizza.
It looks like you are using Amazon product descriptions on your site. I strongly recommended writing unique and original content. Don't just re-write it. You need to write original content.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin