Drug maker Bayer lost trademarks for the names "aspirin" and "heroin" this way in the 1920s. So did B.F. Goodrich, which sued to protect its trademark of "zipper" in the 1920s after the name joined the world of common nouns. Similar cases deemed "escalator" generic in 1950, "thermos" generic in 1963 and "yo-yo" generic in 1965.
It's difficult to quantify how much revenue a company loses when its brand is deemed generic. But companies worry that it breeds confusion among consumers.
To prevent their names from becoming generic, some companies use marketing to reinforce their trademarks. For instance, after its Band-Aid brand name started becoming commonly used to refer to adhesive bandages, Johnson & Johnsons changed its jingle in ads from "I'm Stuck on Band-Aid" to "I'm Stuck on Band-Aid brand."
Kleenex uses "Kleenex brand" instead of just "Kleenex" on its packaging and in marketing and places ads to remind people Kleenex is trademarked. And the company contacts some people who use Kleenex generically to refer to tissue in order to correct them.
"We've worked very hard to keep 'Kleenex' from going the route of 'escalator' and 'aspirin,'" says Vicki Margolis, vice president and chief counsel, intellectual property and global marketing for Kimberly-Clark, which owns Kleenex. "If we lose the trademark, people can use it with sandpaper and call that a Kleenex."