Genericide - Trademark Erosion

Trademark erosion is a special case of antonomasia related to trademarks. It happens when a trademark becomes so common that it starts being used as a common name (an appellative) and the original company has failed to prevent such use. Once it has become an appellative the word cannot be registered anymore – this is why companies try hard not to let their trademark become too common, a phenomenon that could otherwise be considered a successful move since it would mean that the company gained an exceptional recognition.

Vaseline (out of the USA), Hoover (The Hoover Company) or Nintendo (which managed to replace excessive use of its name by the then-neologism game console) are examples of "failed" or "successful" trademark erosion.