The Book, Music, Video, and DVD search indexes have very few parent items. The Apparel, Jewelry, and SportingGoods search indexes have many parent items and variations.

If a parent item is returned in a response, it will not have an offer. Instead, you must find the offers associated with the variations of the parent item. You do this by adding the Variations response group to the request, as follows.

http://ecs.amazonaws.com/onca/xml?
Service=AWSECommerceService&
AWSAccessKeyId=1MEXAMPLEZBG2&
Operation=ItemSearch&
Keywords=Ralph%20Lauren&
SearchIndex=Apparel&
Sort=pricerank&
ResponseGroup=Offers,Variations&
MerchantId=All&
Availability=Available&
Condition=All

The Variations and Offers response groups returns the first ten variations of the parent item and their offers, which is shown in the following response snippet.

<Variations>
  <TotalVariations>6</TotalVariations>
  <TotalVariationPages>1</TotalVariationPages>
  <Item>
  <ASIN>B000FG8I6W</ASIN>
  <ItemAttributes>
    <Binding>Apparel</Binding>
    <Brand>Polo Ralph Lauren</Brand>
    <ClothingSize>10 - 13</ClothingSize>
    <Color>Beige Heather</Color>
    <Department>mens</Department>
    ...
  </ItemAttributes>
  <Offers>
    <Offer>
      <Merchant>
      <MerchantId>A1T5FLMGQ4PRAI</MerchantId>
      <Name>Polo.com</Name>
      </Merchant>
      <OfferAttributes>
        <Condition>New</Condition>
          <SubCondition>new</SubCondition>
    </OfferAttributes>
    <OfferListing>
    <OfferListingId>WjQ49eW5WwGDJ4Ga6u06Il56YzTQKzVh0G2ag0k9vZtbjcojcnUwkkbogxg6dzeDmu9alzXSn04nz0DvdnZT8gqeiRSRRx2shyER2SDHWREJthdUmXvDYO%2Bf0z%2FOdpye</OfferListingId>
    <ExchangeId>Y11M5192166M4119841</ExchangeId>
    <Price>
      <Amount>1400</Amount>
      <CurrencyCode>USD</CurrencyCode>
      <FormattedPrice>$14.00</FormattedPrice>
    </Price>
    <SalePrice>
      <Amount>560</Amount>
      <CurrencyCode>USD</CurrencyCode>
      <FormattedPrice>$5.60</FormattedPrice>
    </SalePrice>
    <Availability>Usually ships in 1-2 business days</Availability>
  </OfferListing>
</Offer>
</Offers