Depending on the type of CSS and the model, a merchant can place their ads on to the Google Shopping results spaces via a CSS partner, which removes the additional fees charged by Google when using Google's own comparison engine (Google Shopping Europe - GSE). This makes your bid to auction much more competitive, reducing your CPCs by up to 20%. A Merchant can choose what level of service they want when selecting an appropriate partner and can either continue to manage their own activity as normal, with the added CSS CPC benefit, or they can opt for partner that manages activity and places those product ads on behalf of the merchant.