Attributed to a Microsoft exec in the 80s: https://www.geekwire.com/2025/eat-your-own-dog-food-how-micr...
In 2015, Marc Andreessen memorably said of Mixpanel's success at product-led growth: "The dogs are fucking jumping through the screen door to eat the dog food. And he hasn’t done any marketing yet." https://www.newyorker.com/magazine/2015/05/18/tomorrows-adva...
That then led to the idea of "eating your own dog food", because if even you won't eat it, what credibility do you have saying that the other dogs will?
Without being able to cite a specific TV ad or other urban legend sort of baseline, it clearly communicated that you hold yourself and your products to a higher standard. As a dog-food producer, you don't just meet the minimum requirements for legal sales, but you make it well enough to be fit for human consumption too.
It's in the same category as someone demonstrating that they could safely drink or breathe byproducts of some other industrial process. And, ironically, there was also a widely understood corollary that we could expect PR types to do something like this while secretly fearing that it would actually harm them.