You may now set the "offers" parameter to "Featured" in ECS 3.0 AsinSearch requests. Setting "offers" to "Featured" will allow you to retrieve featured merchants' offers using ECS 3.0. A featured merchant is a vendor with whom Amazon has a special partnership and whose offers are prominently featured on Amazon product detail pages. Prior to now, accessing featured merchants' offers was only possible in ECS 4.0.
Here is a sample ECS 3.0 AsinSearch request that shows how this new parameter value works:
Remember to replace "SUB_ID" with your developer token or subscription ID and "ASSOCIATE_TAG" with your own Associate ID or "webservices-20". Since featured merchants do not exist on Amazon.co.uk, Amazon.de, and Amazon.co.jp, this new parameter value only applies to the US version of ECS 3.0.