Customers sometimes want to shop from sellers they've grown confident in. You can enable the customer to see all of the items one seller has for sale by using the SellerListingLookup operation. By default, it uses the SellerListing response group, for example:

http://ecs.amazonaws.com/onca/xml?
Service=AWSECommerceService&
AWSAccessKey=[AWS Access Key ID]&
Operation=SellerListingSearch&
SellerId=[Seller ID]&
ResponseGroup=SellerListing

The following response shows one of the seller's items that they have for sale. The entire response contains all of the seller's items.

<SellerListing>
  <ExchangeId>Y06Y0322155Y6575786</ExchangeId>
  <ListingId>0909R298811</ListingId>
  <ASIN>0451205367</ASIN>
  <Title>Richest Man in Babylon [Paperback] by Clason, George S.</Title>
  <Price>
    <Amount>273</Amount>
    <CurrencyCode>USD</CurrencyCode>
    <FormattedPrice>$2.73</FormattedPrice>
  </Price>
  <StartDate>2005-09-10</StartDate>
  <EndDate>2008-08-25</EndDate>
  <Status>Open</Status>
  <Quantity>293</Quantity>
  <Condition>new</Condition>
  <SubCondition>new</SubCondition>
  <Seller>
    <SellerId>ASYDZOX0HKBSE</SellerId>
    <Nickname>any_book</Nickname>
  </Seller>
</SellerListing>