I just joined with amazon web service to get "access key" so I can pull product information with XML. But I also read on Amazon web service that it's inexpensive ? So what I have to pay for ? If I get product info with ASIN I also get view detail page which url contains also my access key like is affilate link or something. Please clear me up. Can't make head or tail out of it ( I hope i spelled it rightly) Thanks