You wouldn't even have to make it addictive

You know what industry is pretty much recession proof? Toothpaste. It's not like people are going to stop brushing their teeth. It'd have to be extremely bad for folks to even try to consciously use *less* toothpaste. There's not a lot of room for growth, though. You can steal other toothpaste manufacturer's customers, but you can't really turn non-customers into customers. I suppose you could develop a toothpaste that canceled out the effects of The Pill, added latex-dissolving properties to semen, and made you really horny. That way you'd at least be making *new* customers for your line of toothpaste products. Still. I have to imagine there would be some liability there.