Amazon celebrated its 20^th anniversary in style last week, hosting Amazon Prime Day to reward its members with big deals. Amazon was the real winner though. The company sold more units – 34.4 million to be exact – on Prime Day than Black Friday 2014, the company’s biggest Black Friday sale ever. Breaking it down further, 398 items were ordered on Amazon Prime per second! Worldwide growth increased 266% over the same day last year and 18% more than Black Friday 2014.

In addition, more members tried Prime, Amazon’s subscription service, worldwide than any single day in Amazon history. According to Amazon, customers ordered hundreds of Amazon devices on Prime Day as well, making it the largest device sales day ever worldwide.

In a press release, Greg Greeley, vice president for Amazon Prime, said, “Going into this, we weren’t sure whether Prime Day would be a one-time thing or if it would become an annual event. After yesterday’s results, we’ll definitely be doing this again.”

In spite of the financial success, some customers and media outlets have complained that Amazon wasn’t well stocked enough, and they took to social media and Amazon’s review feature to share their ire. Amazon’s numbers speak for themselves. There are still a lot of happy people out there.

Amazon has grown a lot since its early days selling books out of a Seattle garage, says the Associated Press. Amazon is now a global retail powerhouse bringing in $89 billion of annual revenue, a $15 million increase over 2013. In addition to bringing in the big bucks, Amazon has a fair amount of hits and market innovations to its credit. Here’s a look at some of the changes we’ve seen since Jeff Bezos, Amazon founder and CEO, started Amazon in July 1995.

Amazon Successes

Amazon Marketplace: Started in 2000 to compete against eBay, Marketplace is a platform for third-party sellers to offer their wares under the branding umbrella of Amazon. According to the Associated Press, 40% of Amazon’s units are sold by more than two million third-party sellers around the world. If you can buy it, you can probably buy it on Amazon – books, movies, craft supplies, pet supplies, clothing, groceries, cameras, and more.

Amazon Prime: Launched in 2005, Amazon Prime was created as a perk to Amazon’s most loyal customers. Originally sold for $79.99, a Prime membership

To feed that growth, Amazon has had to expand, adding fulfillment centers and increasing the number of items eligible for Prime shipping. The company now has more than 20 million items eligible for two-day shipping and 109 warehouses worldwide. Free shipping, quickly becoming a consumer expectation, has changed consumer habits, says Greeley.In an interview with The Post’s Hayley Tsukayama, Greeley said tens of thousands of members joined the first day of the launch, and four out of five of those early adopters are still members. In 2011, Amazon introduced Prime Instant Video, Fire Tablets and a lending library for Kindle owners and growth increased even further.entitled members to free two-day shipping and access to Amazon’s streaming video library. Now $99.99, Amazon has tens of millions of subscribers, according to The Washington Post (also owned by Bezos). In the past year, memberships have increased 53%, and during the holiday season last year, 10 million people subscribed to Amazon Prime.

“People originally came for all-you-can-eat two-day shipping, then found out the menu included so much more,” he said in The Post interview. “Having the menu of benefits allows us to do all we can for those tens of millions of members.”

The real benefit to Amazon of the Prime membership is that members are more engaged, Greeley said.

“…we’re top of mind – they don’t have to drive around for a hard-to-find item. On the app or on the PC, they’re engaged on the other benefits as well,” he said.

In the company’s 2014 investor statement, Bezos explained the success of Prime.

“When we raised the price of Prime membership last year, we were confident that customers would continue to find it the best bargain in the history of shopping. The data is in and customers agree – on a base of tens of millions, worldwide paid membership grew 53% last year – 50% in the U.S. and even a bit faster outside the U.S.,” he said.

“Prime is a one-of-a-kind, all-you-can-eat, physical-digital hybrid – in 2014 alone we paid billions of dollars for Prime shipping and invested $1.3 billion in Prime Instant Video. We’ll continue to work hard for our Prime members.”

Amazon Web Services: In 2006, Amazon launched Amazon Web Services (AWS) to provide a suite of business products and services using remote services, now known as “the cloud.” The offering was based on Amazon’s unique knowledge developed from its work creating its highly successful e-commerce platform. Well-known brands like Adobe, Airbnb, Dow Jones, The Guardian, Hearst and Intuit all use Amazon’s cloud services, saving time and money. According to Amazon’s first quarter 2015 financials, revenue for the most recent quarter of AWS was up 49% to $1.57 billion.

Amazon Kindle: Amazon launched the first black-and-white Kindle in 2007, the same year the iPhone was “born.” Though nothing like its modern-day counterpart, the Kindle allowed users to download books to its e-reader without having to connect to a PC. In a 2011 article by Bloomberg Business, Tim O’Reilly explained the importance of this innovation.

“I spent literally decades trying to get publishers to pay attention to e-books, and I know how resistant they were to the idea,” said Tim O’Reilly, the founder of computer book imprint and conference organizer O’Reilly Media. “Most publishers just weren’t willing to move. Jeff made them all move, and he took a bold bet on hardware and got into a different business that didn’t necessarily play to Amazon’s strengths.”

The Kindle wasn’t the first e-reader and investors were skeptical, but Kindle had its strengths. It could be used as a stand-alone device and users could access Amazon’s then-catalog of 90,000 or so titles. Much has changed – including the design and functionality of the Kindle – since its 2007 launch, but together Amazon and Kindle are a significant part of the e-book revolution.

Kindle Fire TV: According to Amazon in a January article on Yahoo! Finance, Kindle Fire TV is the best-selling streaming box on its own site. Like Roku and Chromecast, Kindle Fire TV, unveiled in 2014, is both a streaming video set-top box and a “stick” that allows owners to stream services like Netflix, YouTube and Hulu on a television. Strategic Analytics, an independent research firm, reported in the first quarter of 2015 that Fire TV accounted for 30% of all streaming set-to-box shipments in the U.S., or 3.5 million units in the first quarter of 2015.

On Prime Day alone, Prime members ordered tens of thousands of Fire TV sticks in one hour, making it the fastest-selling deal on an Amazon device ever.

Amazon Failures

While Bezos and Amazon have done a lot of things right in the last 20 years, Amazon has had some failures as well. Some were very public failures like the Fire phone and Living Social, and others were for products and services you probably never heard of – 50+ Active and Healthy Living Store, Kozmo.com (shampoo delivery in an hour), Askville.com (a crowdsourced Q&A site), and Kindle and Instant Video apps for iOS.

The Fire phone was perhaps the biggest flop, said Fortune magazine. Introduced in June 2014, the phone never really took off, causing Amazon to drop its price to $0.99 to get rid of it. At a Business Insider Ignition conference in New York last December, Bezos said it was too soon to analyze what went wrong, but he expects Amazon to make mistakes as it innovates.

“My job is to encourage people to be bold,” Bezos said. “I’ve made billions of dollars of failures at Amazon.com. Literally billions. Companies that don’t embrace failure and continue to experiment eventually get in the desperate position where the only thing they can do is make a Hail Mary bet at the end of their corporate existence.”

The Big Picture

For the year ended December 31, 2014, Amazon had a net loss of $241 million. At the end of 2013, it had net income of $274 million. So far, 2015 doesn’t look much better. For the first quarter of 2015, the company’s net loss was $57 million. Compare this to net income of $108 million for the first quarter of 2014. That’s a $165 million swing year-over-year. For the second quarter of 2015, Amazon is predicting an increase in net sales, and operating income between $50 million (gain) and $500 million (loss).Amazon is guided by four principles: customer obsession rather than competitor focus, passion for invention, commitment to operational excellence, and long-term thinking. These tenets seem pretty solid 20 years later, but Amazon is operating at a loss.

4 Subscription Lessons from Amazon

Innovation and Risk are necessary for success: Amazon is not afraid to be innovative, nor is it afraid to take risks. As part of its culture, the company is willing to try new things, to tweak and change them, and reprice them if needed, until they find just the right mix. And when a product or service tanks, they cut it loose and admit defeat.

Give your subscribers something they can’t get anywhere else: Amazon Prime is one of the company’s biggest successes. Though it has evolved since its initial launch, Amazon Prime continues to be a bargain for the loyal shopper who uses Amazon as its primary online shopping resource. Amazon continues to sweeten the pot by adding new products and services to subscription service, like the addition of Prime Now and the recent Prime Day. Despite the consumer complaints, you can’t argue with the financial success of Prime Day.

Set the standard: The Amazon marketplace shopping cart was one of the first, and it is now the norm for most online retail shopping. Amazon has made it even easier with 1-click shopping, and we anticipate Amazon will continue to be the leader in this area.

Launch, measure, tweak, repeat: Amazon is always measuring its success – and not just by looking at the financials. They look at Prime subscription numbers, identify trends, and perhaps most importantly, they have followed their Prime customers from inception to see what their retention rate is – 4 out of 5 Prime members are still with Amazon, 20 years later! By measuring their success, or lack thereof, Amazon can make intelligent, fact-based decisions moving forward.

We can’t wait to see what the next 20 years hold!

Dana Neuts is a Reporter-Contributor for Subscription Insider.