最初由 aruba 发布
let me use examples to show my understanding of them.
If you have a store that is located on a crowded street,people walk/drive by will see the sign of your store. This may bring you a lot of business. So your customer are based on walk-by traffic.
contrarily, if the store is located on a quiete street, the only way of attract new customer is that you provide good service. then your current customers will refer you to his/her friends. This way is called word of mouth.
I hope this helps.