Best way to test consumer reaction to sustainable packaging?

Surveys are fine but conjoint analysis will give you much stronger data — it forces shoppers to make real trade-offs between packaging, price, and other factors rather than just saying 'yes I care about sustainability' (they always say yes). If budget is tight, even a simple A/B test on shelf with eye-tracking can show you whether the eco packaging actually gets noticed. Tools like Qualtrics or even a quick Wynter panel can get you results fast.