The 1980's were famous for wars - USA vs. USSR, Coke vs. Pepsi, and Burger King vs. McDonalds ... Wendy's threatened to make it a 3-way race, thanks to an elderly lady used in a very famous ad campaign.
Clara Peller was an 84-year-old retired manicurist ... somehow, she was chosen for a Wendy's commercial, in which she was ordering a burger from a fast-food company (called Big Bun). When Peller receives her burger, she utters what would become a mid 1980's anthem, "Where's the Beef?" This one comment rocketed Peller to instant stardom. Wendy's burger sales jumped 30% almost overnight. Peller became a frequent guest on late night shows, and she even made cameos on tv shows and movies.
And one way to know you've become famous is when sex jokes are made in your honor ... I believe the "Where's the Beef" quoe was responsible for a dirty joke book.