How one woman built a 7-figure business selling cat doors on Amazon
Lisa Harrington is the founder of Purrfect Portal.Courtesy of Lisa Harrington
Lisa Harrington’s e-commerce career began on eBay. She sold anything she could find in her closet.
In 2012, she used eBay revenue to launch her first product on Amazon: Dog Harness.
Her second product, Interior Cat Door, became a bestseller, bringing seven numbers.
Lisa Harrington felt she wasn’t full of need for her corporate life and side projects.
“I really didn’t like my job. It didn’t go anywhere. So for fun, I just sell things from my closet on eBay, my old wallet, shoes, whatever I can get,” she told Business Insider.
As items in her closet fell, she thought the next logical step was to create her own product and sell it online.
“I just fell into this e-commerce research hole, this whole world where you can analyze supply and demand,” she said. “In the end, I found a dog niche.”
She decided to sell dog harnesses, found the manufacturer through Alibaba and ordered stock worth around $5,000 using eBay revenue. The product arrived at her doorstep and “it took me three hours to get to the second floor, as it was a carton after the carton after the carton,” she said.
Harrington listed and sold most of her initial inventory on eBay.
This was 2012, but when it was on sale on Amazon it was still in unknown territory. But when she discovered a relatively new platform and created the list, she said, “sold out within 24 hours.” “And I did math. If I actually kept this in stock, how much do I spend a year on income? And it was simply $1 million.”
Her immediate success on Amazon probably had more to do with timing than her products.
“In 2013, 2014, it was easy because there weren’t many options,” she said. “Every year it gets harder.”
For years, Harrington sold dog harnesses while working 9-5. She ran a lean business from her home in Arlington, Massachusetts, using the internet as a business coach.
By 2016, her e-commerce profits matched her salary and she had quit the unhappy job that encouraged her to start a side project in the first place.
Having earned an extra 8 hours a day, she launched her second brand. purrfect portalFills the gap in pet space.
Harrington has designed and patented multiple interior cat doors.Courtesy of Lisa Harrington
“I’m a cat woman – I’ve always been a cat woman – and I really wanted an indoor cat door,” Harrington said. “When I went online, there was only one option.”
And that wasn’t great, she added: “It was typical, ‘I can do this better.’ I know how to do this.
Still, designing a cat door is a completely different and complicated project than producing a dog harness. Mentors she found through her business program Score He connected her with engineers and manufacturers who help create plastic products.
Her pussy door was informative, but not an immediate smash hit.
“It was the smallest of my two businesses and it grew side by side with each other each year,” Harrington said.
Her solution to the anguish of her clients came from happy hours with friends.
“Someone said, ‘How about miniature doors? A small human door with a small doorknob and a small window and a small door knocker,” recalls Harrington. “And not only did everyone lose consciousness, but even non-cat people. And in my gut, I knew people would love it.”
It took two years to make the vision of Happy Hour come to fruition, but when it launched in 2020, “people just lost their minds,” she said. “It got to the top of our bestseller list pretty quickly. We were selling 100 units a day.”
In 2025, “We are number one selling cat doors on Amazon and have great patent protection for our inventions,” she added. BI confirmed its seven-figure revenue by reviewing the Amazon Sales Dashboard.
Earning money on Amazon in 2025 is more difficult than ever, said Harrington, who offered three advice to future sellers.
First, if you can’t find a reliable manufacturer, you may fail before listing your products.
“They can make or break your business in terms of really producing something of high quality, and there’s also the trust in wiring money to the other side of the world,” Harrington said.
After working together in the same factory for nearly 10 years, she Unpredictable tariffs. By October, “80% of our catalog is scheduled to be made in the US, but this wasn’t on my bingo card,” she said.
Switches do not reduce costs. In fact, production in the US would cost her more. But she said that peace of mind was worth it. “I honestly had sleepless nights around tariffs. I’ve been doing this for 10 years. I was in a scenario where I could either double my product cost overnight or triple overnight and I was no longer in a scenario where I couldn’t handle that stress.”
Harrington and his team of three employees work remotely.Courtesy of Lisa Harrington
The next ingredient in a successful recipe is networks. You want to be surrounded by people who already do what you are trying to do.
A key perk for membership is access to events that Harrington can connect directly to peers.
“You’re leaving behind notes and pages of things to do,” she said. “There’s always one conversation – it can take five minutes or an hour, but you just have to completely change what you work on when you get home and there’s a random conversation with someone.”
Finally, to make money on Amazon in 2025, you need to offer excellent and unique products.
“In some cases, it’s really hard to compete like that as an American brand because it’s a factory or a brand that has a lower cost of products,” she said. “I think you need to have a moat to be truly successful on Amazon today. And moats can be either sourced in the US, very difficult to make, or intellectual property like practical patents.”
Once you have selected your product, you should “make it as amazing as possible, set low prices, and spend time on advertising.”
