You know, I do not think it is necessarily looks, I do not think I am the prettiest girl... Everyone has something that is their asset, some have the hair, some have the cheekbones, others have the lips. But once you know what is your asset, then you should capitalize on it.
In Irish law, busking is considered vagrancy - you can be arrested for it. It's risky asking people for money in public. So it's not like it's a high-art job. And people who do it as a high-art job make very little money.