The 30 most popular products from last year's Amazon Prime Day - including the ones that surprised us

The Roomba 671 was no surprise at all given that it was at its lowest price ever. This intelligent robot vacuum uses a proprietary three-stage system to clean everything from fine particulates — like dust — to larger debris like sand, hair, and sizeable crumbs. It's Alexa-enabled, so you can control it with your voice or with the available smartphone app. You can read more about the vacuum here.

For Prime Day, Amazon discounted its Audible service by 66%, meaning new subscribers could get four months at $4.95 per month rather than $14.95. Audible gives you access to one audiobook credit per month (which never expire) and 30% off additional audiobooks.

Among our own readers, the No. 3 best seller was a promotional deal Amazon ran on Kindle Unlimited — a departure from past years dominated by tech. With the deal, Prime members who hadn't yet tried the service could sign up for three months of Kindle Unlimited, and get access to over 1 million books, for just $1. The service usually goes for $30 for the same time frame.

The Instant Pot is not at all surprisingly in fourth place, especially seeing as the site sold a whopping 300,000 of them on Prime Day.

Depending on the model you get, you can feed families of 6+ in one fell swoop, and it can replace 10 common kitchen appliances with one: it's a pressure cooker, slow cooker, rice cooker, yogurt maker, cake maker, egg cooker, sauté pan, steamer, warmer, and sterilizer. It also has 16 smart programs, which includes Soup/Broth, Meat/Stew, Bean/Chili, Cake, Egg, and Slow Cook, among others.

Even without a sale, it's a small kitchen appliance with big impact. It's also top of our list for the best instant cookers.

Few people who invest in a Dyson vacuum ever regret doing so. The powerful suction drives deep into surfaces to remove dirt, dust, and debris, while the cord-free design makes it convenient to move around your space. It also filters the air as you clean, so your home will be cleaner from top to bottom.

The 23andMe DNA test offers personalized genetic reports to help you learn about your ancestry, traits, and certain aspects of your health. All you do is take a sample of your saliva, send it to the company's lab, and wait for results.

This discount was a good excuse to finally switch out the old, unsupportive mattress lurking in your room. It helps that Tuft & Needle's mattresses, made with its signature pressure-relieving adaptive foam, are well-received among shoppers already. They're easy to set up, they have medium firmness and support, and they come with a 10-year limited warranty.

Our pick for best portable air conditioner became a top-seller perhaps because it was the dead of summer and shoppers couldn't take the stifling heat in their homes any longer. This ultra-quiet unit is easy to maintain because it has an advanced self-evaporating technology. It's also great because its use extends past summer, turning into a heater or dehumidifier.

The ECOVAC robot vacuum has a max mode cleaning setting for when you need to clean with double the power, and it's as easy as switching it on in the app or by remote. It works with Alexa and Google Home voice commands and has a 100-minute life battery as well as auto-return charging.

With the Amazon Fire TV Stick, you can stream media to any TV with an HDMI input. Popular services like Netflix, Hulu, HBO Now, Showtime, Sling, and NBC are all available in addition to Prime Video. With Alexa capabilities, you can control the TV with your voice. The Stick is small enough to take with you when you travel, so you can plug it into a hotel TV, too.

The Fire TV Stick on sale last year was the older generation model. The link above is for Amazon's newest Fire TV Stick.

At just $160, Eufy's vacuum was a great value buy. It's only about three inches tall, allowing it to sneak under tables and couches to tackle the dirt of the most difficult to reach areas. The vacuum can run for 1.5 hours at a time, then recharges automatically.

Any time Bose discounts its products this heavily, people tend to respond enthusiastically. This pair works particularly well for travelers thanks to its comfort and noise-canceling feature. They were sold at the lowest price we've ever seen over Prime Day.

Another tech brand not known for deep discounts, Sony was a predictable success given their name recognition and how great their products are. This pair's noise cancellation adjusts to your environment with One Push and promises 35 hours of battery, as well as quick charging. There's a built-in microphone for hands-free calls and use with your voice assistant.

The Echo features Dolby speakers that play 360° audio with clear vocals and dynamic bass response, plus seven microphones so it can hear your commands even as music is playing. Available in three different fabric finishes and one wood finish, it doesn't look too bad either, blending into living room or kitchen setting.

The Amazon Echo Dot is a miniaturized, unobtrusive iteration of Amazon's popular smart home device. Play music, set alarms, send messages, look up information, control your Alexa-connected TV, turn lights on-and-off, and much more, all with your voice.

If you've never tried one out before, we have a guide to help you make the most of its features.

The newest Echo Show combines the speaker quality of the Echo and Echo Plus with the visual capabilities of the Echo Spot, and now has a larger (10") HD screen and eight mic array. Make a video call to a friend or family member, watch and follow recipe videos hands-free, and pull up the lyrics to sing along to your favorite song.

The Echo Show on sale last year was the older generation model. The link above is for Amazon's newest Echo Show.

A third over-ear, noise-cancelling option: Sennheiser's vibrantly crisp headphones. Reviewers warn that it's not the most comfortable for large heads, so proceed with caution. Other than that caveat, however, it's a solid set for its price. It also has an impressive battery life of 19 hours, and up to 25 without the noise-cancelling feature.

The most popular Kindle was $40 cheaper on Prime Day. It has a high-resolution display (300 ppl) and an adjustable built-in light. It's lightweight, comfortable to hold, and lets you download millions of books with the click of a button instead of trying to shove a few more onto your bookshelf or in your backpack.

The Kindle Paperwhite on sale last year was the older generation model. The link above is for Amazon's newest Kindle Paperwhite.

The small screen of the Echo Spot lets you video chat, watch videos, and see content at a glance. The compact size makes it perfect as a bedside smart alarm clock — one that gives you a glimpse of front door cameras, thermostat and garage door control, and more.

Philips Sonicare says its popular electric toothbrush removes up to seven times more plaque than a manual toothbrush. There are five brushing modes: Clean, White, Sensitive, Gum Care, and Deep Clean.

Right now, the Galaxy S8 is at its lowest price, but at the time, shoppers were saving more than $200 on this smartphone. To enjoy its large screen and high-quality camera without committing to a mobile provider contract, get this unlocked phone for less than $400 right now.

The LifeStraw removes bacteria and parasites from water as well as microplastics, so you can have the peace of mind of a lightweight, mobile water purifier wherever you go. It's a no-brainer for hiking, camping, travel, and being prepared for an emergency, especially since a small water purifier is harder to get your hands on than band-aids.

But even given its incredible utility, Amazon selling 150,000 still came as a surprise to most.

See exactly who's standing at your door and finally catch your neighborhood package thief with this smart video doorbell. It monitors your home in 1080HD video with infrared night vision, then sends alerts to your phone or Echo device when motion is detected.

An Oral-B electric toothbrush being sold for less than $40 kind of speaks for itself, especially since the genre is usually dominated by numbers that edge closer to $100.

Enjoy the riches of cafe-quality espresso at home with this Breville machine. It's a bit of a splurge, as most espresso machines are, but it comes with everything you'll need (save for the beans) and it's pretty easy to use.

So you have a handful of smart devices scattered around your house. Now it's time to get organized and connect them to one central hub. The Samsung SmartThings kit works with a wide range of devices including lights, speakers, locks, thermostats, and sensors.

At the end of a long day of deals-hunting, nothing feels better than resting your head on a comfortable pillow. It has a 4.3 rating from more than 16,000 reviews because of its luxurious microfiber feel and adjustable memory foam fill.

In another deal that was too good to go unnoticed, Amazon discounted the Cloud Cam by 50%.

The smart device can send notifications to your phone when it senses motion, allowing you to travel with peace of mind knowing you can stream video on demand to see what's going on. It features night vision, two-way audio, and Amazon Alexa capability.

You can stop ironing with this steamer on hand, which heats up in under a minute, can be used on all types of fabrics (including delicates) and releases wrinkles faster than ironing.

Fitbit's slim but powerful fitness tracker does everything from track your deep and REM sleep to help you find the right workout intensity for your fitness goals.