If you join through a "Comparison Shopping Service partner" (hereinafter referred to as CSS partner), Google will give 20% Shopping CPC advantage from regular search results over advertisers without a CSS partner!
In other words, if you don't already have a Google "CSS partner", you now have a 20% CPC disadvantage over competitors that do have a CSS partner.
Many web shops already advertise via a "CSS partner" on Google. This can be seen in the Shopping search results that there is something other than "from Google" at the bottom, but for example "from BestChoice ":
Due to a court ruling at EU level, Google is obliged with their regular search engine to give other comparison sites a chance on the basis of a level playing field. Google has implemented this by automatically giving CPC bids that run through a CSS partner a 20% higher bid, compared to CPC bids, without a CSS partner. The origin of this is that the judge has indicated that “Google Shopping” must also be seen as CSS and must also make a profit.
Comparison site https://BestChoice.shop is CSS from Google, to give ESS customers the 20% advantage of Google. Plus possible (free) clicks from comparison site BestChoice.shop
If you instruct us for "CSS membership", Google will link existing campaigns without you having to do anything (Ads campaign management remains unchanged). In addition to the CPC benefit that Google gives, you may also be able to receive (free) clicks through the CSS partner's comparison site.