The Instant Pot — a seemingly magical multi-cooker — has grabbed the attention of Amazon shoppers and food fanatics around the world. Behind the product is CEO and founder Robert Wang, who has built the business with little marketing and an obsession with improving the product. Wang, who has a PhD in computer science with a specialty in artificial intelligence, keeps three Instant Pots running at his house at all times, and he's read almost all of the reviews on Amazon — that's more than 39,000 for the most popular DUO60 6 Qt 7-in-1 Multi-Use Programmable model alone. "I try to read every single one," he tells CNBC Make It.

Founder Robert Wang at home with his three Instant Pots. Courtesy of Robert Wang

Users of the fast and convenient pot — which functions as both a pressure cooker (cooking things rapidly by trapping steam) and a slow cooker (heating food low and slow) — are just as obsessed as Wang. On Amazon, they compulsively post reviews that mark their devotion to the gadgets, which can also be used as a rice cooker, yogurt maker, sauté/browning pan, steamer and warming pot. "This device has changed the way I cook! LOVE LOVE LOVE it!!!" writes one reviewer; "This has transformed meal preparation in our house," says another. The praise continues in the Instant Pot's Facebook group, which has over 750,000 members. The group gained more than 10,000 members in 30 days from mid-October through mid-November, and can see as many as 7,000 posts each day. On the page, users exchange recipes, tips, tricks and, of course, rave reviews. Fans also take to Instagram and Pinterest.

Reviewers on these platforms include regular people, as well as bloggers — some of whom have been gifted the cooker to test out. Shelley Moser, a mom of three girls in North Carolina, tells CNBC that she simultaneously uses two Instant Pots to cook things like rice and beef with broccoli. "I'm hooked. It's like a whole other world opens up," she says. Moser bought her Instant Pot on Amazon's Prime Day and she is certainly not alone. The annual promotion by the e-commerce giant brings landslide sales to Double Insight, Wang's Ottawa, Canada-based company. In 2016, 215,000 Instant Pot 7-in-1 Multi-Functional Pressure Cookers were sold on Prime Day. This year, Instant Pot topped the Prime Day Best Sellers list again for both the U.S. and Canada. Instant Pots, which cost about $50 to $150, depending on retailer and model, are also a bestseller during the holidays. Wang says that on Black Friday and Cyber Monday last year, Instant Pots far outsold Prime Day. And according to Amazon, the 6-quart Instant Pot 7-in-1 Multi-Functional Pressure Cooker was a top-three bestselling kitchen product during that time. This Black Friday, Instant Pots were a best-selling item at Kohl's, CEO Kevin Mansell tells CNBC, selling out by Friday morning. CNBC reports J.C. Penney was sold out too, while Target and Wal-Mart appeared to keep it in stock through the afternoon.

Wang declines to give numbers for overall Instant Pot sales, but says "We've been more than doubling year-over-year from 2011," in both revenue and unit sales. Indeed, Instant Pot is a leader in the multi-cooker category, "which grew 56 percent in the last year and 85 percent the year before. Over the last three years, about 5 million units have been sold," according to NPD stats reported by CNBC. For Wang, the demand highlights a growing consumer need for quick healthy dinners. Like many Instant Pot customers, Wang uses his three Instant Pots to make meals for his busy family. "For example in the morning, my daughter needs to have an egg to get started, and she is really picky regarding eggs," he says. "She wants a soft-boiled egg with a runny yolk inside and the whites well-cooked." So, he turns to the Instant Pot. Other family favorites include porridge with beans, ribs and sweet corn on the cob.

A history of convenience

Slow-cooked dinners bubbling away while home-cooks are at work is nothing new. The Crock-Pot was invented over 75 years ago, when Irving Nachumsohn received a patent for a very early version of the device in 1940. It surged to popularity in the 1970s as women began broadly entering the work force, according to the Washington Post. An advertisement for Crock-Pots in Sept. 25, 1975 ran in the Post and argued the product was "perfect for working women." A study by Carnegie Mellon University found that household appliances (like Crock-Pots) accounted for about 40 percent of the increase in married women heading to work during the 1960s, the Post points out. And, the low energy aspect of Crock-Pots became crucial for households during the oil and energy crisis in the 1970s. "While women may have fallen in love with the Crock-pot for the convenience it afforded, America fell in love with it for the money it saved," Cnet reports. Wang cites the invention of the first rice cookers as even earlier in the 20th century, and a pressurized cooking pot was made in the 17th century by the French physicist Denis Papin, according to The New York Times. But Wang's business is centered on the idea that those products haven't kept up with the times. "Our parents and our grandmothers lived a very different life," he says. "Those legacy appliances haven't evolved that much to cater to the needs of our generation." So, Wang decided to make something different.

The invention

In 2008, Wang was working at a mobile messaging company that he co-founded, but as the economy turned down, the venture became harder to pursue. "I realized that it is difficult to continue on building high-tech companies because it was almost impossible to get funding," he says. So Wang and two friends began to brainstorm other business ideas and noticed they all struggled to cook healthy dinners while balancing work and kids. "We did lots of takeout, fast food, and we know that is not good enough for our children," he says. "So that is why we were thinking, 'What if there is a machine which is smart enough, which can automate the entire cooking process for us, so that we can fix dinner when we come back from work.'" Enter, the Instant Pot. In 2009, they founded the company and launched their first product in October of 2010 on Amazon. (Since then, Wang has brought on new partners.) During that time, the focus was inventing the best product possible. "We have done lots of experiments, my partners and myself have done a lot of cooking," Wang says. "This is more that just eating our own dog food. It is like force-feeding dog food." When they started selling their first version, "The first batch of customers were family and friends," he admits. Then word spread. "So after the first generation of product, we gathered enough feedback to make modifications," says Wang. The company added features like burn protection and the cooker started to take off. Wang cites the tipping point as January 2013, when the company's second-generation Instant Pot initially became the bestseller in the pressure cooker category on Amazon. "I realized we had captured the imagination of the public," he says. Today there are more than 10 versions of the Instant Pot on its website, and it can be found in at a slew of retailers like Williams Sonoma, Target and Best Buy. The expansion is largely due to word of mouth. "To be honest with you, we haven't spent much money on advertising," Wang says. "In fact, that is not part of the business plan. We really spend money on product development and customer support."

The reinvention