Making a little research, an interesting question showed up: When is a brand really strong? When we think about that, it's really huge the number of possible answer we might get. The most intriguing one? When people start faking it.
Yeah, you may think this is stupid, but if you only think about it for one moment, you'll realize that only solid brands are copied in industrial scale. Adidas, Puma, McDonald's, Panasonic are among the brands that are so famous that people will even get absurd copies of their products.