The Similarities response group returns the title and ID of items that are similar to those returned in a response. For example, in the following sample request.

http://ecs.amazonaws.com/onca/xml?
Service=AWSECommerceService&
AWSAccessKeyId=[AWS Access Key ID]&
Operation=ItemLookup&
ItemId= B000184IY0&
ResponseGroup=Similarities

the following similar item was returned:

<SimilarProduct>
  <ASIN>B00004GJVO</ASIN>
  <Title>Minor Move</Title>
</SimilarProduct>

You can use the information in this response to display the titles of similar items. If you want to display more information about the similar items, use the ASIN returned in a new ItemLookup request and specify an appropriate response group, such as ItemAttributes.