Embodiments of computer implemented systems and methods for comparison shopping are described. One example embodiment includes receiving a data resource associated with a web page, the web page including an offering of a product and product offering terms, extracting product descriptors from the data source, requesting a search of marketplace offerings of the product based on the product descriptors, receiving results of the search (the results including marketplace offering terms of the marketplace offerings of the product), and displaying the marketplace offering terms, thereby facilitating comparison of the product offering terms with the marketplace offering terms.