How do I create a default brand in feed?

If all your products are of the same brand (example: Your Brand) and you want to define this in your feed without updating each product one by one, in the advanced commands area type:

To create a default brand in Google feed:

setAttributeDefault brand as "Your Brand Name"
mapAttribute brand to g:brand

To create a default brand in Amazon feed:

deleteAttribute brand
setAttributeDefault brand as "Your Brand Name"
mapAttribute brand to brand
setParam localized_name "Brand Name"

Replace “Your Brand Name” with the brand/vendor name.
Keep “Brand Name” as is, as it is Amazon’s required local label for the brand field.

For other merchants:

setAttributeDefault brand as "Your Brand Name"
mapAttribute brand to [merchant-brand-attribute-name]

Replace [merchant-brand-attribute-name] with the target’s attribute brand name. For example, Bing’s brand attribute name is simply: Brand