Last July, Amazon touted the success of its second annual Prime Day promotion in a press release, rattling off how much stuff people bought in different categories:

I'm sorry--wait, what? Pressure cookers? And more than that, why the focus on a specific brand of pressure cooker?

At this point, readers of this article will separate into two (and only two) categories. There are those who, like me, last heard the phrase "pressure cooker" mentioned either in the context of people being too stressed or when some terrorist puts together an improvised bomb. (No links for that one, for obvious reasons.)

Then there are those whose reaction is more like: Yes, no kidding, the Instant Pot--here are the first seven things you should make with one when you buy it.

Because it turns out that the Instant Pot is a calculated viral phenomenon. And there's an innocuous, interesting, and perhaps even inspiring story behind it.

How to make a product go viral

Background: The Instant Pot is a product of a small Canadian company, founded by engineers (as opposed to say, chefs or experienced entrepreneurs). It has 25 employees, no traditional advertising to speak of, and an Amazon-centric sales strategy.

Its primary marketing strategy? Social media, which leads to word-of-mouth promotions.

Over the last six years, since it first hit the market, the company "has provided free Instant Pots to 200 bloggers and cookbook authors who represent many styles of cooking, including Chinese, Italian, sous vide, and vegan," according to NPR.

(By the way, NPR says Instant Pot was the "top-selling item in the U.S. market" when they reported on it; it seems to have dropped to the No. 2 item in Amazon's Kitchen and Dining section--no longer tops, but still impressive.)

In any event, those bloggers and authors loved it. They came up with recipe after recipe and review after review, giving the company tons of free publicity. The Instant Pot's owner's manual and the company's website featured these crowdsourced recipes, ensuring that even customers who bought the product on their own have a chance to get sucked into the virtual Instant Pot community.

"Cooking is very much a social behavior," the company's CEO explained to NPR. "If people make good food, they will be raving about it, including the tools used."

And just about everything the company does is designed to fan the flames of that kind of free, word-of-mouth advertising.

Product first, marketing second

The Instant Pot retails at $99. During Amazon's Prime Day it was discounted to $69--but that still means the company sold $14.8 million worth of pressure cookers in a single day.

It has 15,278 reviews on Amazon as of this writing, and an average rating of 4.5 stars. (Don't take that as an endorsement or encouragement on my part to buy one; I've never even seen one of these things in real life. I'm just impressed by the sheer volume.)

Sure, savvy marketers game Amazon all the time, but the only way to generate that kind of response is if people actually love the product. My colleague Candice Galek reported recently on something Tim Ferriss said, when he was asked how he'd drive traffic to a new brand if he had a budget of only $5,000:

"Use the $5,000 to have experiences and then write about them."

I've been thinking about that quote all week--how the first thing that matters is your product. If you're writing for, it's the quality of your content. If you're making pressure cookers, it's how good they work.

Do it well enough, and in an age of social media, people will share what you've come up with to their friends and followers. It's just that easy--and that hard.