How do you track consumer preferences shifting toward sustainable packaging?

Conjoint analysis has been our go-to for this — it forces respondents to make real trade-offs between packaging, price, and brand rather than just saying sustainability matters (which everyone does). We ran one for a snack brand last quarter and found eco-packaging only moved the needle when price delta was under 8%. Also worth layering in actual shelf-test data if your client can swing it, since stated vs. revealed preference gaps are huge in this category.