Bidmagpie

Insights

Practical articles on Google Shopping, CSS partnerships, and performance marketing for UK and EU retailers.

What is a Google CSS, and why should retailers care in 2026?

A clear explanation of Google Comparison Shopping Services, the EU ruling that created them, and what they mean for your Google Shopping campaigns.

Jack Chittenden · 7 min read

The 20% auction advantage, explained without jargon

Google takes a margin from Shopping bids placed through its own CSS. Third-party CSSs don't pay that margin. Here's what that means in practice.

Jack Chittenden · 5 min read

CPA vs CPC vs flat-fee CSS partnerships: which is right for your retail business?

The three commercial models for CSS partnerships compared head to head. Risk, control, and where each one fits.

Jack Chittenden · 7 min read

How Google Shopping bidding actually works inside the carousel

A technical but readable guide to the Google Shopping auction: second-price mechanics, quality score equivalents, and why position isn't just about bid price.

Jack Chittenden · 6 min read

Will a CSS partner cannibalise my own campaigns? The mechanics of second-price auctions

The most common objection to CSS partnerships, answered with auction mechanics rather than sales talk.

Jack Chittenden · 5 min read

A retailer's checklist before partnering with a CSS

Eight things to verify before signing with a Comparison Shopping Service. Due diligence that takes 30 minutes and saves months.

Jack Chittenden · 5 min read

Microsoft Shopping vs Google Shopping: how the two stacks compare for UK retailers

Google dominates Shopping in the UK, but Microsoft's network is growing. A side-by-side comparison of reach, cost, and opportunity.

Jack Chittenden · 5 min read

Affiliate channel vs paid media channel: why CSS sits in both

CSS partnerships blur the line between affiliate and paid media. Here's how to think about attribution, budgeting, and team ownership.

Jack Chittenden · 5 min read