1. Because some advertisement cause people to buy the product of what the advertising is about like using celebrity or attractive model and that lead to consumption of fortune.
2. I think is no. We could check the product before we buy it that way we could not waste our money and the company that make this product will not make this anymore because they know that no one is going to buy so less resource to make that product.
3. I think yes. Some of the product had really good advertising technique that make you or your friend. They can use celebrity or model to attract the costumer to buy their product.