Do you agree or disagree that people often buy things that they don't really need?

I'd say people often buy things they don't need because shopping has become more about the experience than just the product. Take Nanjing Road in Shanghai - when I go there with friends, we might buy small souvenirs or snacks we didn't plan to get, just because the lively atmosphere makes us want to participate in that moment. That said, I don't think it's necessarily wasteful - sometimes those little purchases create nice memories with friends, which lasts longer than the actual item.