What are the real margin impacts of offering free shipping above a threshold on D2C orders?

Free shipping thresholds are now essential for D2C but significantly erode margins post-logistics. One member's detailed analysis found that while they projected 78% of orders would fall below their £50 threshold (and thus incur shipping costs to the customer), the actual figure was 60%—meaning 40% of orders attracted free shipping. This 20-percentage-point miss meant they absorbed full pick, pack, and shipping costs on far more orders than modelled, collapsing website margins to levels comparable with on-trade and off-trade channels. The key lesson: free shipping thresholds are now table-stakes for D2C competitiveness, but members should model conservatively (expect lower conversion to paid shipping than intuition suggests) and stress-test margin impact before committing.