How it works
The CSS model, the auction advantage, and why it doesn't interfere with your existing campaigns. In plain English.
What is a Comparison Shopping Service?
In 2017, the European Commission fined Google €2.4 billion for favouring its own comparison shopping service in search results. The remedy created a new market: third-party Comparison Shopping Services can now bid for placements in the Google Shopping carousel on behalf of any merchant.
A CSS operates a genuine price-comparison website where consumers can search and compare products across multiple retailers. Once approved by Google, the CSS can submit product listings to Merchant Center and bid in the Shopping auction on behalf of its merchant partners.
“Third-party CSSs get the same Shopping placement at up to 20% less cost. That margin is the entire business model.”
Where Bidmagpie sits in the picture
From your existing feed to a confirmed sale, in six steps.
Your product feed
Your existing Shopping feed and affiliate programme stay exactly as they are.
Affiliate network
We connect through Awin, CJ, Webgains, TradeTracker, or Rakuten. No new contracts.
Bidmagpie optimises
We manage bids, targeting, and Shopping placements under our CSS licence.
Google Shopping carousel
Your products appear in Shopping results, attributed “by Bidmagpie”.
Consumer clicks through
Traffic goes directly to your product page. No interstitial, no detour.
Sale tracked, CPA paid
Conversion recorded in your affiliate dashboard. You pay commission on the sale only.
The 20% advantage, explained simply
When a merchant bids through Google's own Shopping surface, Google takes a margin of roughly 20% before the bid enters the auction. Think of it as a house fee.
When a third-party CSS like Bidmagpie places the same bid, that margin is removed. The full bid enters the auction. Either we win more auctions at the same cost, or the same auctions at a lower cost.
We pass that advantage through as incremental Shopping placements your own campaigns aren't winning.
Same £1.00 bid, different effective auction power
20% margin retained by Google
Full bid enters the auction
Result: 25% more bidding power per pound spent
Why it doesn't cannibalise your existing campaigns
Google's Shopping auction has a specific rule: a merchant cannot be forced to compete against itself. If your campaign and our CSS campaign both bid on the same auction, Google enters only the higher bid. The lower one is discarded.
But we go further than relying on auction mechanics alone. We use sophisticated title and description optimisation algorithms to rewrite your product data specifically for the queries your original feed isn't targeting. Your feed is optimised for your campaigns. Ours is optimised for the auctions you're not in.
This means we're not just bidding on the same queries at a different price — we're surfacing your products in searches your current feed doesn't match against. That is genuinely incremental traffic that would never have reached your site otherwise.
You're already winning the auction
Our bid is automatically discarded. Your CPC stays the same. No change whatsoever.
Optimised titles target different queries
Our algorithms rewrite product titles and descriptions to match searches your original feed doesn't rank for. Entirely new traffic, not a redistribution of yours.
Your bid is below the auction threshold
Our CSS advantage means we can clear the threshold you couldn't. You get a sale you'd otherwise have missed.
What you'll see in your reports
No new dashboard. No new reporting tool. Bidmagpie appears as a publisher in your existing affiliate network, with full sale-by-sale transparency.
| Publisher | Clicks | Conv. | Revenue | Commission | Conv. rate |
|---|---|---|---|---|---|
| BBidmagpie | 2,847 | 142 | £18,430 | £1,474 | 4.99% |
| CCashback partner | 1,203 | 67 | £8,120 | £650 | 5.57% |
| VVoucher site | 4,510 | 89 | £11,240 | £899 | 1.97% |
Microsoft Shopping runs in parallel
Google dominates search, but Bing, Yahoo, DuckDuckGo, and Edge collectively carry 10–15% of UK search traffic. We run Microsoft Shopping campaigns for every retailer alongside Google, on the same CPA terms.
Microsoft Shopping has no CSS equivalent — the advantage there is simply lower competition. CPCs run 30–50% cheaper than Google, and the audience skews higher-income, which typically means stronger average order values.
You see one combined publisher line in your affiliate dashboard. We handle the feed, the bidding, and the optimisation across both platforms. No additional setup on your side.
Why both networks matter
Google Shopping
~85% of UK search traffic. CSS advantage. Volume leader.
Microsoft Shopping
~10–15% of UK search. Lower CPCs. Higher AOV audience.
Combined via Bidmagpie
One feed, one CPA rate, one publisher line in your dashboard.
21 markets. One partner.
Every Google CSS-eligible market in Europe, plus Microsoft Shopping coverage in additional territories.
See it in action
We'll walk you through the setup, show you sample reports, and tell you honestly whether your category is a fit. 20 minutes.