There are two different feeds: Amazon feed (http://shopperita.com/admin/structure/feeds/amazon_feeds) and ebay feeds (http://shopperita.com/admin/structure/feeds/ebay_feeds - disabled to reduce node creation). Both are connected to a content type (Amazon Feed and Ebay Feed content type). The parent nodes are created by the custom modules (custom_amazon, custom_ebay,, and custom_shops).
Both feeds create nodes of type "Product"
Amazon parent nodes are refreshed before processing as amazon api uses a timestamp.