"What’s the Difference between Ketchup and Catsup?"

"'Well, catsup has more tomatoes, comes in a bigger bottle. It’s cheaper, but tastes just like ketchup. Now,' she continues, 'we know that’s not true. But that’s what your competitors are saying, over and over. And they’re selling their watered down, flavorless sauce by pretending that they’re you. It makes you mad, doesn’t it,' she adds.
"It does. But wait a second. Is there a difference between ketchup and catsup?"

Aisha Harris answers the question in Slate.