Whitelabel for brands and retailers
Whitelabel is usually framed as an agency product. For a large merchant the logic is different and in some ways stronger: you are already generating the impressions, and they are currently branding someone else.
The situation
A retailer running significant Shopping spend generates millions of impressions a month, each carrying a "By" line. Under a third-party CSS, every one of those impressions puts a supplier’s name under your product. Under your own, it puts yours.
For a brand that spends real money on awareness, that is a channel it already owns and is currently giving away.
Doubling the brand presence on the results page
Your product listing already carries your merchant name. Adding your brand to the attribution line means your name appears twice in the same unit, in a position no competitor can buy. On a results page where six retailers compete for the same product, that is a real difference in recall.
This is one of the few brand-visibility gains in performance marketing that costs nothing per impression and cannot be outbid.
The clicks come home
The share of Shopping clicks that land on the attribution link currently leaves your ad and arrives on a third party’s comparison site, frequently one that also lists your competitors. With your own CSS, those visitors land on a property you control.
What it costs a merchant
The same platform fee as an agency pays, against a much larger impression volume. For a retailer whose Shopping spend is in the tens of thousands a month, the branding argument alone clears the cost by an order of magnitude before the CPC advantage is counted.
What it does not solve
Running your own CSS does not change your auction terms, which are equal by regulation whichever CSS you use. It does not improve your feed, and it does not reduce your dependence on Google. It changes whose name is on the work you are already paying for.