Your Free Shipping Threshold Should Shape Your Bidding Strategy
Free shipping above £50. It's a conversion lever, an AOV driver, and an abandonment trigger - all at once. But most Google Ads accounts treat every product identically regardless of where it sits relative to the threshold. That's leaving money on the table and wasting it simultaneously.
How Thresholds Change Bidding
Your free shipping threshold creates two distinct customer experiences:
- • Products above threshold: Customer gets free shipping. Higher conversion rate. Lower abandonment. Worth bidding more aggressively.
- • Products below threshold: Customer hits surprise shipping cost at checkout. Higher abandonment. Conversion rate drops 15-25%. CPCs become less efficient.
If you're bidding the same amount for both groups, you're overpaying for below-threshold products and underpaying for above-threshold products. The fix is segmentation.
Above vs Below Threshold Economics
Calculate the real CPA difference between products above and below your threshold:
- • Above threshold products: 3.5% conversion rate, £1.80 CPC = £51 CPA. Free shipping costs £4 but is absorbed by higher margin on higher-priced products.
- • Below threshold products: 2.2% conversion rate (checkout abandonment), £1.50 CPC = £68 CPA. Plus the customer pays shipping, reducing their perceived value.
The above-threshold products are 25% more efficient on CPA and deliver higher customer satisfaction. Your bid strategy should reflect this gap.
AOV Clustering Around Thresholds
Look at your AOV distribution - you'll typically see clustering just above the free shipping threshold. Customers add items to reach the threshold. This is good for AOV but changes the economics:
- • The add-on items may be low-margin (customers add the cheapest thing to hit the threshold)
- • The free shipping cost eats into the margin of the threshold-crossing order
- • But the total order margin is usually still higher than a below-threshold order with paid shipping
Track the margin of orders at different AOV bands relative to your threshold. This tells you whether the threshold is genuinely driving profitable behaviour or just inflating revenue.
Feed Signalling
Make your threshold work harder in your product feed:
- • Set shipping costs correctly so above-threshold products show "Free delivery" badge
- • Use custom labels to segment products by threshold position (
custom_label_4: above_threshold|below_threshold) - • Consider including "Free delivery" in product titles for above-threshold items (test CTR impact)
Campaign Segmentation
Structure your campaigns around the threshold:
- • Above-threshold campaign: Higher ROAS target (these products convert better). Higher budget priority.
- • Near-threshold campaign (70-100% of threshold): Products likely to trigger add-to-cart behaviour. Good conversion rate with upsell potential.
- • Below-threshold campaign (under 70%): Lower ROAS target to account for checkout abandonment. Or consider bundling these products to reach the threshold.
Testing Threshold Changes
If you're considering changing your threshold, model the Google Ads impact first:
- • Lowering the threshold: More products qualify for free shipping badge, improving CTR and CVR across more of your feed. But shipping cost increases.
- • Raising the threshold: Fewer products qualify, more abandonment on mid-price products. But higher AOV on qualifying orders.
- • The optimal threshold maximises (conversion rate improvement × margin) minus (shipping cost increase)
Next Steps
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