40% of ecommerce customers increase their return shipments when informed about the negative environmental consequences of product returns!
This is what a team from the Universities of Frankfurt and Mannheim showed in a large-scale, randomized field experiment (published here by Marketing Science, a top peer-reviewed journal). This study really stands out due to its sample size (> 100k consumers!).
That ‘s the bad news (for a summary of nudges backfiring, check out this overview). But there is also good news:
- 👍 The dual green nudge (example in the graph below) did not affect conversion rates and overall sales negatively.
- 👍 The researchers were able to effectively target the green nudges to the consumers most likely to react positively, using causal machine learning.
- 👍 Green nudging “seems to be particularly effective for consumers who would otherwise return at an above-average level”, as the authors put it.
Also, as the authors point out, the consumers where the nudges backfires may not be anti-sustainability monsters, but simply customers that are unintentionally reminded by the nudge that returns are possible.

So, what’s the takeaway? If you’re going to nudge, nudge wisely! This study is a good reminder that not all green nudges are created equal—some might just nudge customers straight to the return label. But with a little finesse and some causal machine learning magic, you can turn those nudges into a win-win: happy customers and a happier planet. Let’s keep it green, but also keep it smart. 🌍✌️

