Free shipping on orders over $100

National Geographic
August 2014
Control and variation


The National Geographic Society has been inspiring people to care about the planet since 1888. It is one of the largest nonprofit scientific and educational institutions in the world. The National Geographic team wanted to improve the conversion of their webshop and started by testing a simple free shipping offer.


 Adding a free shipping offer will increase revenue.


Improvement wk1 Improvement wk2
Free shipping (no threshold) +18,9% +2,2%
Free shipping over $50 +33,8% -11,4%
Free shipping over $75 -98,9% -25,8%
Free shipping over $100 +14,6% +4,8%


Offering free shipping indeed increases revenue. But the team was surprised about the results:

The original expectation was that free shipping for all purchases would produce the highest revenue lift, and that as minimum purchase thresholds rose, revenue would decline. However in week 1 the threshold of $50 and in wk 2 the threshold of $100 outperformed the ‘no threshold’ offer. A possible explanation could be that the average order size increases as people buy more or more expensive items to qualify for free shipping.

The second surprise concerns the big difference in results between week 1 and week 2. This shows that results can dramatically shift in time. It would be interesting to see the results over longer periods of time.

Test details

Test element Banner
Page type All
Test date August 2014

Website information

Company National Geographic
Market Digital products, E-Commerce
Test result
Test element Banner
Page All
Result +5% revenue

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