Amazon is of course one of them. A major player in the sales game, the online giant has some huge discounts across every category, including Amazon devices, TVs, gaming, laptops, home appliances, beauty products, kids’ toys and a whole lot more.
Follow live: The best Black Friday deals to shop now
But, that’s not all. In addition to impressive savings on big-ticket items, such as the Nintendo Switch consoles, Echo dot smart speakers and Apple iPads, the retailer is also offering a great deal on Audible. New customers can get three months of membership for just 99p – but the offer is only available until 30 November, so you’ll need to act fast.
There’s no denying that Amazon is one of the best places to shop this Black Friday, but with so many deals up for grabs, it can be tricky to know where to start.
Thankfully, here at IndyBest, we have put together this guide to all the best early Black Friday deals you can snap up now. Happy shopping!
The best early Amazon Black Friday 2021 deals to shop now
Best Amazon own device deals
Amazon Kindle paperwhite, 32GB: Was £119.99, now £79.99, Amazon.co.uk
Whether you’re an avid reader or shopping for a bookworm, now is the time to snap up a Kindle. The device took the top spot in our guide to the best ereaders, with our writer noting that it’s “a big step up from the entry-level Kindle”. It features “a high-resolution screen which is extremely easy to read” and the “design is elegant with the screen flush to the frame”. If you’d rather have the option to download your books away from wifi, then you’ll be glad to know the 3G Kindle paperwhite (was £219.99, now £129.99, Amazon.co.uk) is also reduced, which gives you the option of accessing new books by the pool.
Amazon Echo dot, 3rd gen: Was £39.99, now £18.99, Amazon.co.uk
Amazon’s Echo dot speakers are some of the hottest items on Black Friday, partly because the online giant slashes the price of its own-brand products by a ridiculously large amount. And third-generation model currently has a whopping 53 per cent off. In our review of the latest Echo dot, our tester said of the range: “Amazon’s smart speakers are wildly popular, with good reason: Alexa is easy to set up, simple to navigate and the speakers themselves are of a high quality.”
Amazon Fire TV stick 4K max: Was £54.99, now £36.99, Amazon.co.uk
“Amazon’s Fire TV collection has been at the forefront of streaming since the first product arrived on the site in early 2014,” noted our writer in our round-up of the best Android TV boxes. Our tester praised this model for being “very smart” and found that navigation was “smooth”, with apps opening “almost immediately”. It is also “probably the best-value mainstream streaming device on the market”, and with the current Black Friday saving, it’s even more pocket-friendly.
Amazon Echo show 8, 1st gen: Was £99.99, now £59.99, Amazon.co.uk
As Amazon released its second-generation Echo show 8 model earlier this year, there’s a great saving to be had on the older version of the device. Released in 2019, this model gives you rich stereo sound, allows you to set alarms, ask for weather and news updates, display pictures and access streaming services such as Spotify. Plus, if you connect your EE or Vodafone mobile phone account, you can also answer calls on your show.
Amazon Echo dot, 4th gen: Was £49.99, now £28.99, Amazon.co.uk
One of Amazon’s bestselling home devices, this smart speaker currently has 42 per cent off for Black Friday. Promising crisp vocals and balanced bass, you can use it to listen to music and the radio while also controlling your entertainment by asking it to play tunes, podcasts and audiobooks from streaming services. The device earned a spot in our round-up of the best smart speakers, with our reviewer saying Alexa is “easy to set up, simple to navigate and the speakers themselves are of a high quality”.
Amazon Fire HD 10 kids pro tablet: Was £199.99, now £109.99, Amazon.co.uk
Amazon has an impressive range of kid-friendly devices and this one is the retailer’s latest offering. Having reviewed this model, we can confirm it’s “hard to fault”, with our writer noting that “it’s fun, easy to use and with the comprehensive parental controls and decent guarantees, it’s basically hassle-free, and all encased in some pretty decent, grown-up tech”. With such high praise, and 45 per cent off, what are you waiting for?
Amazon Echo show 5, 2nd gen: Was £74.99, now £39.99, Amazon.co.uk
You can save nearly 50 per cent right now on Amazon’s popular Echo show 5 device. Not just your run-of-the-mill smart speaker, the device also enables you to video chat, make calls, set alarms, watch movies and more. The compact 5.5in display is perfect for streaming your favourite TV shows or catching up on the news, while access to everything from Prime Video to Netflix means you’re always up to date with the latest releases. If you need further convincing, when our writer reviewed the device for a previous version of our round-up of the best smart speakers, they praised the “front-facing camera, making it great for video calls” and added that the “the screen is useful for visual indications of everything from the weather to sports results”.
Amazon Echo dot kids, 4th gen: Was £59.99, now £33.99, Amazon.co.uk
With a nearly 50 per cent saving on Amazon’s own Echo dot kids device, there’s no better time to invest in a smart speaker for your little one. In our review of the savvy gadget, our writer praised the vast amount of content available thanks to the Amazon Kids+ subscription, as well as the advanced parental controls. “It’s incredibly cute, and there’s enough content on Amazon Kids to keep even the most inquisitive child happy almost endlessly,” they said.
Amazon Echo buds with charging case, 2nd gen: Was £129.99, now £99.99, Amazon.co.uk
Newly launched and a noticeable step up from Amazon’s original Echo buds, this second-generation, pocket-friendly pair are smaller, more lightweight, sweat-resistant and fine in light rain. There are also four earbud sizes and two wing-tip sizes for increased comfort, and they now feature noise cancellation (unlike their predecessors). Battery life is also strong with five hours of playback on a single charge while the case gives you two extra charges – totalling 15 hours of playback. Right now, you can save more than 20 per cent.
If you’re finding it difficult to encourage your kids to get reading, then perhaps something a little techy could help them get interested. While we’ve not reviewed this exact model, Amazon’s Kindle comes highly commended in our guide to the best ereaders, with our writer praising the high-resolution screen for being “extremely easy to read” and the design for being “elegant with the screen flush to the frame”. This model comes in a bright colour and with one year’s Amazon Kids+ included, giving your little one access to Harry Potter, Geek Girl and more.
Best early Amazon gaming deals
Nintendo Switch bundle with ‘Mario Kart 8 Deluxe’, ‘Just Dance 2022’ and a three-month Nintendo Switch Online membership: Was £378.99, now £284.99, Amazon.co.uk
This is an excellent bundle deal on the Nintendo Switch console in the neon red and blue colourway. You’re essentially buying the Nintendo Switch and then getting Mario Kart 8 Deluxe at half its usual price. But then, to sweeten the deal even further, you’re also getting Just Dance 2022 and a three-month Nintendo Switch Online membership for free. As usual, you’ll get two neon joy-cons and a Switch dock for TV play out of the box.
HTC Vive cosmos VR headset: Was £699, now £499, Amazon.co.uk
Can you hear that? It’s the loud, completely virtual jingle jangle of the metaverse, and it’s the future. If you want to get ready for it, then HTC’s Vive cosmos VR headset is currently on sale at Amazon, which has kindly knocked a whole £200 off its recommended retail price. The PC-tethered headsets features inside-out tracking, a six-camera tracking faceplate and a crisp 3.4in 2880 x 1700 resolution LCD display. With an ever-growing catalogue of VR games on Steam and the Viveport, you’ll always have a virtual world to fight boredom.
Razer blackshark v2 X wired gaming headset: Was £59.99, now £35.99, Amazon.co.uk
Razer’s blackshark v2 X currently has 40 per cent off at Amazon. It features a 50mm audio driver that the company promises sounds like three drivers in one. Gamers are able to tune high, mid and low audio frequencies individually. The microphone also features a bendable design so that you can position it as near or far away as necessary. The slightly more expensive Razer blackshark v2 pro is our top pick in our round-up of the best gaming headsets, so you know you’re in good hands.
Best Amazon early home appliance deals
Philips wake-up light alarm clock: Was £140, now £84.99, Amazon.co.uk
If you’re not a morning person, then the solution is to invest in a sunrise alarm clock. And we’ve got just the one for you. This one has previously featured in our review of the best light-up alarm clocks, where our writer praised the gadget’s ability to mimic a holiday-worthy sunrise. There are 20 brightness settings, different natural sound choices, and an FM radio setting. If that’s not enough to persuade you, the brand is clearly one you can trust as a similar model took a spot in this year’s round-up too. Snap this up now and say goodbye to those groggy mornings.
Hotel Chocolat velvetiser, copper: Was £109.95, now £89.99, Amazon.co.uk
‘Tis the season for hot chocolate and now is the best time to upgrade your drinking experience by investing in Hotel Chocolat’s popular velvetiser. Akin to a traditional milk frother, the machine works by simultaneously heating and whisking milk and hot chocolate together to create a silky smooth mixture with a frothy top. In our review of the velvetiser, our tester said it “felt really luxurious” and made “each drink feel like a mini experience”. Just don’t forget the marshmallows.
Tower xpress pro T17039 vortx digital air fryer: Was £119.99, now £73.99, Amazon.co.uk
If you’re looking to cook up a healthy storm, then an air fryer is the answer. This featured in our review of the best, with our writer praising the rotisserie chicken, “which was cooked to perfection in under an hour”. It has other talents besides air frying, including its ability to “bake, roast or dehydrate”, and features three separate mesh racks for cooking different foods at any one time. A great all-rounder.
Nespresso vertuo plus XN903840: Was £189.99, now £79, Amazon.co.uk
Getting your caffeine fix has never been simpler, or cheaper, than with the Nespresso vertuo plus. From just one machine you will have the choice of five different cup sizes – ranging from espresso to alto – as well as three different capsule sizes, from small to large. We loved it so much that it took one of the top spots in our round-up of the best pod coffee machines, where our tester said it was “incredibly easy to use” and that “a lovely smooth crema wasn’t just confined to the single and double espresso but was even waiting for us atop the huge (414ml) alto drink that the machine produced”.
Shark upright vacuum cleaner NV602UK lift-away: Was £249.99, now £168.99, Amazon.co.uk
When Mrs Hinch recommends a cleaning brand, it’s good practice to listen up. And now’s the time to save on this Shark vacuum. While we’re yet to review this exact model, a similar one was highly commended in our review of the best pet vacuum cleaners, with our writer praising it for being a “versatile machine”. A key similarity between the two is the lift-away technology that allows the cylinder to disconnect from the body of the vacuum – something our tester found allowed for “more flexibility” when it came to cleaning hard-to-reach spots.
Best Amazon early tech deals
Apple AirPods pro are pretty pricey but, thanks to Amazon’s early Black Friday sale, you can snap them up for a fraction of the cost. In our review of the earbuds, our tester said they “are a high-end pair of earphones that are difficult to find much fault in”. Retaining a similar design to the original AirPods (was £119, now £116, Amazon.co.uk), they feature Apple’s signature glossy white finish but come with three different sized silicone eartips, so you can find the perfect fit for you. As for the noise quality, our tester added that “it’s a sound topped by few rivals,” with an impressive active noise-cancelling function that shuts out ambient noise.
Microsoft Surface go 2, 10in tablet: Was £529, now £339, Amazon.co.uk
Microsoft’s budget tablet is a gorgeous portable device that – unlike the rival iPad and Galaxy tab – runs a full-fat version of Windows and so is compatible with all of the same apps, programs and software you can use on your desktop machine. The Surface go 2 appeared in our list of the best tablets in 2021, where our reviewer described how it can “double as a laptop if you add the type cover (was £124.99, now £101.06, Amazon.co.uk), a sturdy keyboard that fits to the front of the tablet and is sold separately.” The more advanced Surface go 3 launched recently, which is why you can pick up last year’s version so cheaply today.
Apple Watch series 6 with GPS, 44mm, aluminium: Was £409, now £309, Amazon.co.uk
In the market for a new fitness tracker? Amazon is currently offering £100 off the 2020 Apple Watch series 6 with the aluminium casing and a navy sports band. This GPS model lets you take calls, reply to texts and get directions while out and about, although you’ll still need your iPhone close by. It also has a blood oxygen sensor and an ECG monitor, and it’s got an always-on display that Apple says is two times brighter outdoors than the previous series 5.
Google Nest security camera indoor: Was £129, now £69.99, Amazon.co.uk
Enjoy peace of mind while away from home with the Nest indoor security camera. Connecting to Google’s cloud servers so you can take a look at what’s happening (or not happening, ideally) while you’re out and about anywhere in the world. The camera features in our round-up of the best security cameras, where our reviewer praised its intelligent microphone that “can listen for sounds such as glass breaking”. Night-vision is built into this version and there’s no need for fiddly hub boxes or installation, just grab the Nest app on your phone to be connected to your home 24/7. Pay monthly for Nest Aware and you can unlock bonus features such as archived recordings.
Best early Amazon TV deals
Sony Bravia KE65A8/P 65in OLED TV: Was £2,399, now £1,699, Amazon.co.uk
The Bravia range from Sony is well respected for its premium design and quality. In fact, we’ve named the Bravia product as the “best for audio” in our round-up of the best 4K televisions on the market at the moment. This TV features Sony’s X1 Ultimate processor powering the device’s 4K HDR image –meaning there’s dedicated hardware ensuring the best possible picture is delivered. Sony’s clever acoustic surface audio design means that the sound is coming straight from the screen too – invisible vibrations make sure that there’s an exemplary match between what you hear and what you see on-screen.
Samsung QE32LS03TCUXXU ‘the frame’ 32in QLED smart TV: Was £599, now £359, Amazon.co.uk
Exclusive to Samsung, the frame is designed to blend into the background when not in use and looks at its absolute best when mounted flush to a wall, preferably with some clever wire-disguising. It uses light sensors to detect ambient conditions and gently adjusts the brightness and temperature of the artwork displayed on screen to create the impression of a painting. Per pixel QLED lighting means the screen can be completely black in a dark room, enhancing the illusion when the TV is off and creating impressive, immersive contrast when used for watching TV and movies.
Best Amazon laptop deals
Microsoft surface laptop 4, 13.5in: Was £999, now £779, Amazon.co.uk
The surface laptop 4 is a delight to work on thanks to its stylish design, premium finish and sharp display. The laptop appears in our round-up of the best laptops of 2021, and in our full review our tester was suitably impressed by its performance, describing the device as “as near-to-perfect a Windows experience as you can find”. Right now, the entry-level configuration of this top-rated laptop has £220 off at Amazon’s Black Friday event.
Best Amazon beauty deals
St. Tropez self tan express bronzing gel: Was £33, now £17.80, Amazon.co.uk
Top up your winter tan and grab 46 per cent off with this St. Tropez steal. Vegan-friendly, it has a one-hour developing time and the translucent gel formula is infused with hyaluronic acid. An IndyBest favourite, our reviewer put it in the top spot in our best fake tans guide, noting that it is “non-sticky”, “blends effortlessly” and “feels ultra hydrating”. Meanwhile, we rated the St.Tropez x Ashley Graham (was £38, now £25, Amazon.co.uk) ultimate glow kit as best to apply, and it’s also currently reduced.
Panasonic premium wet and dry 4-blade electric shaver: Was £159.99, now £47.50, Amazon.co.uk
We reviewed a similar model in our round-up of the best wet and dry shavers and are always impressed by the power and smooth shave that Panasonic delivers. Complete with four blades and a flexible head for a comfortable and neat shave on the face, this skin-friendly shaver is designed to adapt to the contours of the skin, by ensuring minimal irritation. With a 70 per cent discount, this is a stellar early deal.
Revlon one-step hair dryer and volumiser: Was £79.99, now £48.07, Amazon.co.uk
Taking the top spot in our round-up of the best hot air brushes, there’s a reason Revlon’s one-step went viral on TikTok last year. A two-in-one styling tool that gives the power of a dryer and the volume of a styler, our tester said the brush is simple to use and can be used on all hair lengths. “We loved the way the Revlon one-step dryer and volumiser dried and styled our hair with such ease – its bristles glided through our hair and left us with a salon-worthy blow-dry at an affordable price,” they said. This deal is on a special-edition red model.
Oral-B smart 4 electric toothbrush with smart pressure sensor: Was £199.99, now £69.99, Amazon.co.uk
Nearly all dentists recommend the use of an electric toothbrush, which is why we reviewed the best electric toothbrushes available to buy right now. While this set didn’t feature in our top ten we did review several similar options and think it’s a worthy addition to your Black Friday basket. You get two electric toothbrushes included both of which have app connected handles and several settings which span teeth whitening and pressure control to a sensitive option.
Best Amazon sport and fitness deals
Fitbit versa 2 martwatch: Was £199.99, now £99, Amazon.co.uk
Here at IndyBest, we love a Fitbit. And although this exact model didn’t feature in our best Fitbit round-up, its sister models did, and we also did an in-depth review of the newer versa 3. Sharing a number of the same functions, including built-in Amazon Alexa, continuous heart-rate monitoring, sleep tracking and real-time exercise stats, for those not obsessed with having the latest bit of tech, this could be a great option. Currently on sale with 50 per cent off, this exciting offer will only last for 13 days.
What is Black Friday?
Referring to a weekend-long shopping event – Black Friday traditionally begins the day after American Thanksgiving and runs through to the following Monday, also known as Cyber Monday – marking the beginning of the Christmas shopping season.
This year, Black Friday falls on 26 November, and there will be hundreds of retailers discounting big-ticket items online and in-store.
What’s the history of Black Friday?
The shopping event began as a one-day, post-Thanksgiving sale, as stores slashed their prices to kick off the festive period.
While it’s hard to pinpoint exactly where Black Friday comes from, it’s believed the phrase was coined in the 1960s, when Philadelphia police officers used it to describe the chaotic traffic the day after Thanksgiving. It’s also thought to refer to the period when American retailers make most of their profit, moving from “the red” and into “the black”.
Then, as the internet and social media took off in the Noughties, videos of American shoppers rushing into stores to bag a bargain started to go viral, prompting UK retailers and brands to get in on the trend. Amazon led the way, launching its first UK Black Friday promotion in 2010, and it’s now become a major fixture in Britain, with bigger discounts and more brands participating every year.
When is Black Friday 2021?
For 2021, Black Friday will take place on 26 November, spanning the weekend and finishing on the following Monday.
Amazon’s is typically the biggest of all the sales – in 2020, it launched its early-bird deals in early November, four weeks before Black Friday itself, which was two weeks longer than its 2019 sale period. Discounts began a good four weeks early, and it’s expected that the retailer will follow a similar timeline for 2021.
The online giant also has a dedicated page on its website where it will be announcing details of its 2021 sale in due course.
What is Cyber Monday?
Cyber Monday is the last day of sale prices before Christmas, so it’s your last chance to bag a bargain.
Originally the phrase described the day when web sales would peak ahead of the festive season, but now it’s become another sale event and serves as a great opportunity to find deals you may have missed out on during Black Friday.
What’s the best way to get a Black Friday 2021 deal?
In the run-up to the big day, we’ll be bringing you all the details you need about the Black Friday sales through extensive guides on how to find the best bargains and the biggest offers from specific retailers such as Amazon, John Lewis & Partners, Currys, Argos and Very.
Many retailers, such as John Lewis & Partners and Amazon, allow for a speedier checkout if you register for an account with them. You can enter your delivery details ahead of the sale starting to avoid having to input them every time you place an order, and potentially miss out on a deal.
If you’re purchasing larger items such as a fridge freezer, TV or household appliance, it’s always a good idea to check the guarantees beforehand, as well as being clear on the relevant returns policies. Don’t forget to measure up for these pieces too, not only the space it will fill, but your doorway too.
Additionally, many brands offer access to discount codes and early-bird sales via their newsletters, so if you have a favourite place to shop, make sure you’re signed up with them before Black Friday kicks off.
Some brands and retailers have already started prepping for the big day by launching their dedicated Black Friday pages in advance – this is the case with Argos, Gtech, Dyson, Currys, John Lewis & Partners, Argos and more.
Tips for shopping the Amazon Black Friday 2021 sale
Amazon’s Black Friday sale often sees thousands of products heavily discounted, with many of its own devices, such as the Echo dot speaker (was £49.99, now £34.99, Amazon.co.uk), Ring doorbell (£89, Amazon.co.uk), the Kindle (£69.99, Amazon.co.uk) and Fire tablets (£49.99, Amazon.co.uk), seeing the biggest savings.
To help navigate the mammoth amount of deals, we have a dedicated team here at IndyBest who will be bringing you the biggest and best offers throughout Black Friday.
The best thing you can do is make a list and not stray from it, as this will help you avoid making impulse buys on items you don’t need, and ensure you find deals on items you actually want.
Before it starts, we’d recommend signing up for an Amazon Prime membership. Costing £7.99 a month or £79 annually, it gives you unlimited next-day delivery, access to its streaming services Amazon Music and Amazon Video, and 30-minute early access to lightning deals throughout the year and during Black Friday.
You can also create wish lists with the retailer that allow you to save as many items as you want in one handy place, and, when Black Friday is here, you can swiftly add them to your shopping basket and check out faster.
Lastly, check the RRP prices of items you’re hoping to find in the Black Friday sale, and that way when the discounts begin, you’ll be able to know if it’s a great bargain or not.
What were the best Amazon Cyber Monday deals last year?
Despite Amazon kicking off its Black Friday sale from 15 October in 2020, if you missed out, its Cyber Monday sale had plenty of deals to go around.
The third-generation Echo dot (£24.99, Amazon.co.uk) came down from £39.99 to £18.99 – less than half the original price.
It’s also a speaker that impressed our reviewer in our round-up of the best smart speakers. They said: “It can do all the Alexa-related stuff of the most advanced speakers such as answering questions, turning smart home gadgets on or off, and so on. Radio, podcasts and audiobooks all sound good, with clear vocals. Echo devices can make audio calls to one another and these work well, too.”
The popular NutriBullet 600 (£69.99, Amazon.co.uk) was also reduced, from £89.99 to £57.99. We think it’s perfect for whipping up smoothies, juices and soups.
It is also featured in our review of the best jug blenders. Our tester said: “The ever-popular NutriBullet is always a solid choice for those who are predominantly looking to blend fruit, vegetables, nuts and seeds into smoothies. Although it only uses a 600W motor with one strong setting, its blades rotate at an impressive 20,000 rpm in a cyclonic motion to speedily break down stems, skins and seeds at great speed.”
Where can I find the best Black Friday 2021 deals?
At IndyBest, we’ll be rounding up the best deals and discounts throughout the run-up to Black Friday and Cyber Monday, so make sure you bookmark this page to always be in the know about Amazon’s best deals.
But, if you can’t wait until Amazon starts its big sale event, as always, there are still some great offers available to shop now from the retailer.
For all the information on the best discounts across all the participating retailers, read our guide to the Black Friday sale, and what to expect from the 2021 sale weekend.
For the latest discounts on home appliances, tech, toys and more, try the links below:
Read more on Black Friday 2021
How to get the best Black Friday deals this year – when the sale starts and how to prepare
Best Black Friday tech deals – whether it’s a new phone contract or noise-cancelling headphones, you’ll find the best offers here
Best Black Friday home appliances deals – now’s the time to upgrade your vacuum cleaner or coffee machine
Best Black Friday gaming deals – Xbox or Playstation? Here’s our expert guide to discounts on consoles, controllers and games
Best Black Friday beauty deals – stock up on your favourites across make-up, skincare, haircare and fragrance
Best Black Friday laptop deals – there are hundreds of pounds to be saved on laptops from big-name brands such as Apple, Microsoft and HP
Best Black Friday TV deals – update your at-home cinema experience without paying full price
Best Black Friday fashion deals – whether it’s a pair of boots or a coat, treat yourself to some wardrobe essentials
Best Black Friday kids’ toys deals – get your Christmas shopping done and dusted with offers from Disney, Lego, Playmobil and more
Best Black Friday sports deals – kit out your home gym or build your winter workout wardrobe
Best alcohol Black Friday deals – whether you’re a fan of gin, vodka, tequila, beer or wine, you’ll be able to bag a bargain
Best Black Friday Nintendo Switch deals – whether it’s the OLED, lite or original you’re after, level up with these discounts
Best Black Friday mattress deals – rest easy with big discounts on brands such as Emma, Eve Sleep and Simba
Best Black Friday Aldi deals – the budget supermarket is expected to slash prices on big-ticket items like the Nintendo Switch
Best Apple Black Friday deals – discover rare offers on the brand’s bestsellers, from AirPods to iPhones
Best Argos Black Friday deals – find discounts on everything from kids to homeware, fitness and DIY
Best Boots Black Friday deals – there’s no better time to save on beauty, skincare, electric toothbrushes and more
Best Currys Black Friday deals – for everything from TVs and laptops to kettles and coffee machines
Best Black Friday Dyson deals – bag a bargain on the brand’s corded, cordless and handheld vacuum cleaners
Best John Lewis & Partners Black Friday deals – the high street stalwart will have great prices on fashion, beauty, tech, kids and homeware
IndyBest product reviews are unbiased, independent advice you can trust. On some occasions, we earn revenue if you click the links and buy the products, but we never allow this to bias our coverage. The reviews are compiled through a mix of expert opinion and real-world testing.