Why do companies sometimes use famous people to advertise things?

I'd say companies use famous people in ads mainly because they bring instant recognition and trust. Celebrities are already familiar to most of us, so when they endorse a product, it feels more credible right away. For example, here in Shanghai, I've seen ads with Jackie Chan promoting local brands like Noodle King, and it immediately grabs attention because people associate him with reliability and skill. That said, relying on celebrities can be a double-edged sword. If the celebrity's image changes or they face controversy, it can harm the brand too. So, while it's effective for quick visibility, it's not always a long-term solution.